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INTRAMUSCULAR STIMULATION FOR
CHRONIC MYOFASCIAL PAIN
by
Choi Chun Lau
B.Sc., The University of Hong Kong, 2004
A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF
THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
in
The Faculty of Graduate Studies
(Experimental Medicine)
THE UNIVERSITY OF BRITISH COLUMBIA
(Vancouver)
April 2010
© Choi Chun Lau, 2010
ii
ABSTRACT
Background: Myofascial pain is a common musculoskeletal disorder characterized by
muscles in a contracted state with increased tone and stiffness. It is one of the most
common chronic pain syndromes that lead to disability and lower quality of life, creating
a significant public health and economic burden. Intramuscular stimulation (IMS) is a dry
needling technique that targets specifically chronic myofascial pain and is utilized in
multidisciplinary pain centers around the world. Despite its wide use, the effect of IMS
has been poorly studied.
Methods: We conducted two chart reviews to generate information regarding IMS
effectiveness and the feasibility of conducting a randomized clinical trial (RCT). Success
rate of pain improvement (at least 1 unit reduction on pain score) was documented in
percentage. In addition, an inter-rater reliability test was conducted to assess the
consistency among IMS practitioners in examining patients. Intra-class correlation
coefficient (ICC) and multiple-raters kappa were used to assess the agreement between
practitioners in identifying number of taut bands and identifying taut bands in each
muscle respectively.
Results: From the two chart reviews, we found that a majority of patients (nearly 30%)
had their pain for 10 or more years. Most of them had chronic low back pain. The
percentage of success was at least 34% (95% CI: 25%, 43%) and 30% (95% CI: 22%,
38%) for worst and average pain (last week) respectively. For inter-rater reliability test,
ICC values ranged from 0.64 to 0.77 (substantial agreement) but kappa values of
identifying tender taut band in each muscle were ranged from -0.05 (poor agreement) to
0.46 (moderate agreement).
Conclusion: Chart review showed positive results regarding short-term effect of IMS in
relieving chronic pain and improving pain consequences. Given the difficulty in treating
chronic pain, it is worth conducting a sham controlled RCT to further evaluate the effect
of IMS. Population characteristics and success rate of pain improvement will be used in
justifying the type and size of sample in the design of a RCT. Good consistency among
practitioners in treating patients has to be achieved before conducting the RCT.
iii
TABLE OF CONTENTS
ABSTRACT........................................................................................................................ ii
TABLE OF CONTENTS................................................................................................... iii
LIST OF TABLES ............................................................................................................. vi
LIST OF FIGURES .......................................................................................................... vii
ACKNOWLEDGEMENTS............................................................................................. viii
CHAPTER 1: Introduction ................................................................................................. 1
1.1 Overview......................................................................................................... 1 1.2 Evaluation Strategy......................................................................................... 2 1.3 Structure of Thesis .......................................................................................... 3
CHAPTER 2: Review of Literature.................................................................................... 4
2.1 Introduction..................................................................................................... 4 2.2 Pain and Chronic Pain..................................................................................... 4 2.3 Myofascial Pain .............................................................................................. 6
2.3.1 Definitions........................................................................................... 6 2.3.2 Epidemiology...................................................................................... 6 2.3.3 Symptoms and Diagnosis.................................................................... 7 2.3.4 Perpetuating Factors and Types of Myofascial Pain........................... 8 2.3.5 Pathophysiology.................................................................................. 8 2.3.6 Treatments......................................................................................... 11
CHAPTER 3: Rationale, Objectives and Hypothesis ....................................................... 22
3.1 Rationale ..................................................................................................... 22 3.2 Objectives and Hypothesis.......................................................................... 22
CHAPTER 4: Study 1-Documentation of the Effect of Intramuscular Stimulation to Treat
Chronic Myofascial Pain: A Chart Review....................................................................... 24
4.1 Introduction................................................................................................. 24 4.2 Methods....................................................................................................... 24
4.2.1 Study Design..................................................................................... 24 4.2.2 Study Population............................................................................... 24 4.2.3 Study Procedure ................................................................................ 24 4.2.4 Ethics................................................................................................. 25 4.2.5 Statistical Analysis ............................................................................ 25
4.3 Results......................................................................................................... 26 4.3.1 Chart Review .................................................................................... 26 4.3.2 Telephone Interview.......................................................................... 27
4.4 Discussion................................................................................................... 28 4.5 Conclusion .................................................................................................. 30
CHAPTER 5: Study 2-Documentation of the Effect of Intramuscular Stimulation to Treat
Chronic Myofascial Pain: Second Chart Review.............................................................. 31
iv
5.1 Introduction................................................................................................. 31 5.2 Methods....................................................................................................... 31
5.2.1 Study Design and Sample Size ......................................................... 31 5.2.2 Study Population............................................................................... 32 5.2.3 Chart Review Process ....................................................................... 32 5.2.4 Chart Information.............................................................................. 32 5.2.5 Outcomes .......................................................................................... 33 5.2.6 Practitioners ...................................................................................... 34 5.2.7 Statistical Analysis ............................................................................ 34 5.2.8 Long Term Follow-up ....................................................................... 34 5.2.9 Ethics................................................................................................. 35
5.3 Results......................................................................................................... 35 5.3.1 Population Identification and Follow-up .......................................... 35 5.3.2 Population Characteristics ................................................................ 35 5.3.3 Pain Intensity Change on Brief Pain Inventory (BPI) ...................... 36 5.3.4 Disability and Quality of Life Items on Brief Pain Inventory (BPI) 36 5.3.5 Oswestry Low-Back Pain Disability Index (ODI)............................ 37 5.3.6 Pain Treatment Satisfaction Scale (PTSS)........................................ 37 5.3.7 Predictors for Improvement in Worst and Average Pain Score......... 38
5.4 Discussion................................................................................................... 38 5.5 Conclusion .................................................................................................. 42
CHAPTER 6: Study 3-Assessing the Inter-Rater Reliability of Intramuscular Stimulation
Practitioners ...................................................................................................................... 54
6.1 Introduction................................................................................................. 54 6.2 Methods....................................................................................................... 54
6.2.1 Study Design..................................................................................... 54 6.2.2 Study Sample .................................................................................... 54 6.2.3 Practitioners ...................................................................................... 55 6.2.4 Study Procedures .............................................................................. 55 6.2.5 Clinical Examination ........................................................................ 55 6.2.6 Outcome Measures............................................................................ 56 6.2.7 Ethics................................................................................................. 57 6.2.8 Statistical Analysis ............................................................................ 57
6.3 Results........................................................................................................... 58 6.3.1 Sample Characteristics...................................................................... 58 6.3.2 Inter-rater Reliability of Identifying Tender Taut Bands .................. 58
6.4 Discussion..................................................................................................... 59 6.5 Conclusion .................................................................................................... 60
CHAPTER 7: Summary of Findings, Conclusion and Future Work ................................ 64
7.1 Introduction................................................................................................. 64 7.2 Summary of Findings.................................................................................. 64 7.3 Conclusion from the Three Studies............................................................. 67 7.4 Future Work: Conduct of RCT.................................................................... 67
CHAPTER 8: A Proposal for a Randomized Controlled Trial (RCT) .............................. 70
v
8.1 Title of the Study Proposal............................................................................ 70 8.2 Background................................................................................................... 70 8.3 Rationale ....................................................................................................... 79 8.4 Clinical Relevance ........................................................................................ 80 8.5 Study Objectives ........................................................................................... 81 8.6 Study Hypothesis .......................................................................................... 81 8.7 Study Design................................................................................................. 81 8.8 Sample Specification .................................................................................... 82 8.9 Interventions ................................................................................................. 83 8.10 Allocation of Intervention........................................................................... 84 8.11 Treatment Duration ..................................................................................... 85 8.12 Frequency and Duration of Follow-up........................................................ 85 8.13 Outcome Assessment .................................................................................. 86 8.14 Recruitment................................................................................................. 88 8.15 Retention Strategy....................................................................................... 89 8.16 Sample Size................................................................................................. 89 8.17 Statistical Analysis ...................................................................................... 89 8.18 Trial Management ....................................................................................... 90 8.19 Ethics........................................................................................................... 93 8.20 Budget ......................................................................................................... 93
BIBLIOGRAPHY............................................................................................................. 94
APPENDIX A: ADDITIONAL TABLES........................................................................111
APPENDIX B: HUMAN ETHICS APPROVAL CERTIFICATE...................................113
vi
LIST OF TABLES
Table 5.1: Demographic Characteristics of Patients Not Included in the Analysis .......... 43 Table 5.2: Demographic Characteristics ........................................................................... 44 Table 5.3: Distribution of Pain Intensity Change at Follow-up Using Available Data..... 45 Table 5.4: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Available Data ........................................................................................................ 45 Table 5.5: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Best Case Imputation.............................................................................................. 46 Table 5.6: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Worst Case Imputation ........................................................................................... 46 Table 5.7: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using LOCF...................................................................................................................... 46 Table 5.8: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Available Data ........................................................................................................ 47 Table 5.9: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Best Case Imputation.............................................................................................. 48 Table 5.10: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Worst Case Imputation ........................................................................................... 48 Table 5.11: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using LOCF...................................................................................................................... 48 Table 5.12: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Available Data................................................................................................................... 49 Table 5.13: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Sensitivity Analyses .......................................................................................................... 49 Table 5.14: Results from Pain Treatment Satisfaction Scale (PTSS) ............................... 50 Table 5.15: Results from Multiple Logistic Regression with Response = Worst Pain Improvement ..................................................................................................................... 52 Table 5.16: Results from Multiple Logistic Regression with Response = Average Pain Improvement ..................................................................................................................... 52 Table 6.1: Intra-class Correlation Coefficient (ICC) for Identifying the Number of Taut Bands in Different Regions............................................................................................... 61 Table 6.2: Multiple Raters Kappa of Identifying Taut Band in Each Back Muscle ......... 61 Table 6.3: Multiple Raters Kappa of Identifying Taut Band in Each Hip/Thigh Muscle . 62 Table 6.4: Multiple Raters Kappa of Identifying Taut Band in Leg Muscle .................... 63 Table 6.5: Multiple Raters Kappa of Identifying Autonomic Dysfunction ...................... 63
vii
LIST OF FIGURES
Figure 5.1: Flow Chart for Population Identification……………………………………53
viii
ACKNOWLEDGEMENTS
I offer my enduring gratitude to my supervisor, Dr. Jean-Paul Collet, for all his support,
guidance, assistance and care during my study. I would like to thank my supervisory
committee, Drs. Marc White, Millan Patel and Rollin Brant, for offering critical and
insightful advice. I would also like to thank Dr. Gunn and the staff at Institute for the
Study and Treatment of Pain (iSTOP) for their invaluable input and effort to this project. I
am extremely grateful that I have wonderful colleagues and sweet friends to be always
beside me and share my ups and downs. Lastly, I would like to sincerely thank my lovely
family members for all their support, patience, care, warmth and love.
1
CHAPTER 1: Introduction
1.1 Overview
Myofascial pain or myofascial pain syndrome is a localized muscle pain syndrome that is
characterized by muscles in a contracted state with increased tone and stiffness, and that
contain myofascial trigger points (Simons et al 1999). Myofascial trigger point (TrP)
was defined by Simons (1995, 1999) as self-sustaining hyperirritable spot located in taut
band (contracted group of muscle fibers) of skeletal muscle or its associated fascia with
zone of tenderness. Direct compression or palpation of TrP provokes radiating and aching
type of pain into localized referred area namely referred pain (Wheeler 2004). Myofascial
pain is one of the most common chronic pain syndromes (Gerwin 2001) that leads to
disability and lower quality of life in individuals, creating a significant public health and
economic burden (Weiner 2001).
Patients with TrP present clinical symptoms such as localized or regional deep aching
sensations, hypersensitivity, allodynia (pain evoked by a non-painful stimulus), palpable
nodules or taut bands with local tenderness, muscle weakness and decreased range of
motion at sites of TrP (Borg-Stein et al 2002, Gerwin 2001, Harden et al 2000, Hong et al
1998, Simons et al 1999). Other functional complaints include decreased work tolerance,
impaired muscle coordination, stiff joints and fatigue (Friction et al 1985). Myofascial
pain is highly prevalent in patients with head and neck pain, shoulder pain, low back pain,
leg pain and has been found to be associated with common chronic pain syndromes
including peripheral neuropathy, radiculopathy, temporomandibular joint dysfunction and
complex regional pain syndrome (Gunn 1997, Baldry 2001, Gerwin 2001, Backonja et al
1998).
Treatments for myofascial pain are diverse. General oral pharmacological treatment for
myofascial pain includes non-steroid anti-inflammatory drugs (NSAIDs), opioid,
antidepressants, anticonvulsants, muscle relaxants (Wheeler 2004, Borg-Stein et al 2002).
These medications usually have limited long term efficacy and are often associated with
numerous adverse events (Wheeler 2004). This is the reason why many patients try
2
alternative treatments such as massage and exercises (Baldry 2002, Cummings 2007, Han
et al 1997), transcutaneous electrical nerve stimulation (TENS), low level laser therapy
(LLLT) and dry needling. Although there is limited evidence on the effect of alleviating
chronic pain for some alternative treatments, the whole field lacks serious study. Despite
the presence of different kinds of treatment, patients with chronic myofascial pain
patients are still under-treated (Breivik et al 2006, Robinson 2007).
Intramuscular stimulation (IMS) is a dry needling technique that targets specifically
chronic regional myofascial pain and is utilized in multidisciplinary pain centers. It has
been developed over 30 years and the IMS teaching professionals have been offering
certified IMS training to several hundreds of pain practitioners in Canada, US and
worldwide (including UK, Norway, Denmark, Korea, Malaysia and Singapore) (iSTOP
2007). Compared to Ah Shi acupuncture (a form of acupuncture that targets TrP and taut
band), IMS approach targets not only TrP or taut band at limbs and trunk muscles, but
also the innervated paraspinal muscles along the spine (Gunn 2007). Based on letters and
testimonials it seems that many chronic pain patients appreciated the effects of IMS in
alleviating their pain but there is no solid clinical evidence supporting its effect.
With the wide use of the IMS technique and the absence of good conventional treatment
for chronic myofascial pain, we felt that it was important to evaluate the effect of IMS so
as to better inform patients the IMS effectiveness in alleviating chronic pain.
1.2 Evaluation Strategy
To evaluate IMS efficacy and safety, we wanted to conduct a sham controlled randomized
controlled trial (RCT). In the preparation phase of the RCT, we conducted a systematic
review of patients’ charts in one IMS clinic in Vancouver to assess the IMS effect so as to
help determining the sample size for the trial. The chart review was useful but also
disappointing because there was missing information regarding patients’ improvement
and the chart information was inconsistently recorded among the eight practitioners at the
clinic. A meeting was held with IMS practitioners to discuss the problems and a new
chart was then developed to systematically document patients’ signs and symptoms.
3
With the same objective, a second chart review was conducted 10 months after this new
recording strategy had been implemented as part of normal practice. In addition, an
inter-rater reliability test was carried out to evaluate the consistency of current five IMS
practitioners in examining patients at the clinic. Finally, with all the information from the
two chart reviews and the inter-rater reliability studies, the protocol of a RCT was
developed and has been submitted for funding to the Canadian Institute for Health
Research (CIHR). This thesis aims to present the methodology and results of these
studies which serve as a rationale for the future RCT.
1.3 Structure of Thesis
The thesis is structured as follow. Chapter two reviews the literature of myofascial pain,
available treatments, dry needling and intramuscular stimulation. Chapter three presents
rationale, objectives and hypotheses. Chapter four documents the results of the first chart
review of patients treated at the IMS clinic. As the initial chart review did not provide
enough information regarding the effect size of IMS, a second chart review was
conducted systematically after implementing a new protocol. Chapter five describes the
results from the second chart review. Details of inter-rater reliability test are presented in
Chapter six. Chapter seven summarizes study results, presents general discussion and
concludes the thesis with potential direction of future works. Lastly, chapter eight is the
proposal of a randomized controlled trial that has been submitted to CIHR.
4
CHAPTER 2: Review of Literature
2.1 Introduction
This chapter reviews the literature in relation to the thesis research question. Section 2.2
briefly presents the definition of pain and the burden of chronic pain in the society.
Section 2.3 reviews the definition of myofascial pain (section 2.3.1), its epidemiology
(section 2.3.2), diagnosis of myofascial pain (section 2.3.3), the perpetuating factors
(section 2.3.4), pathophysiology of different types of myofascial pain (section 2.3.5) and
different kinds of treatment available and the associated clinical evidence including
intramuscular stimulation (section 2.3.6).
2.2 Pain and Chronic Pain
Pain is a complex, emotional and subjective experience that is recognized and tolerated
differently by individuals (Pain Resource Center 2002). According to the International
Association for the Study of Pain (ISAP), pain is defined as the unpleasant physical
sensation or emotional experience that is associated with either actual or potential
damage to body tissues or nerves (Merskey 1994).
Pain can be caused by single or multiple pathways. It can be produced by activation of
specific nociceptors (receptors that are sensitive to noxious stimuli) due to external
stimuli or due to diseases or tissue damage. This is characterized as nociceptive pain. It
can also be the result of dysfunction or lesion in nervous system which is known as
neuropathic pain. Finally, it can also arise from psychological factors such as depression
and anxiety (Abram 2006, Robinson 2007, WHO 2008). Clinically, pain is often divided
into two categories: acute and chronic pain (Harold 2003).
Acute pain is a pain sensation with duration from seconds to days. It is usually the result
of activation of nociceptors by noxious stimuli or tissue damage. Acute pain usually can
be efficiently treated by removal of noxious stimuli or treatment of wound or disease and
thus, in general, it does not present a serious burden to patients (Stefan et al 2004).
Chronic pain is a continuous and recurrent pain that persists longer than the temporal
5
course of natural healing or more than three months (Robert 2002). It may persist long
after initial injury or tissue damage has been healed. The reason for the development of
chronic pain is multi-factorial and yet, not well understood. It is therefore difficult to cure
and is a major public health problem worldwide. In 2000, chronic pain was listed as a
disease by the World Health Organization (WHO) (American Chronic Pain Association
2004).
Chronic pain affects millions of people throughout the world. In US, it was estimated 50
millions (about 20%) of people live with chronic pain caused by disease, disorder or
accident (National Pain Survey 1999). A recent survey conducted in 15 European
countries suggested that 19% of adults suffered from moderate to severe chronic pain at
the time of survey being conducted (Breivik 2006). In China, a study showed that 62
percent of Chinese urban people aged between 33 and 55 had suffered from chronic pain
in the back, neck, shoulders and limbs during their life course (People’s Daily Online
2004).
Chronic pain is a frequent cause of disability and has an enormous negative impact on
individual’s quality of life. Chronic pain diminishes patients’ ability to concentrate on
their jobs, exercise, socialize, sleep and perform daily tasks (Weiner 2001) which
engender downward spiral of depression, isolation and loss of self-esteem (Breivik 2006,
Sternbach 1974, Sternbach 1977).
The effect of chronic pain has profound implications to the society. It creates a significant
public health and economic burden to the public (Jensen et al 2004). Chronic pain is one
of the most common reasons that lead people to seek medical care; patients with chronic
pain use health services up to five times more frequently than the rest of the population
(Blyth et al 2004, Von et al 1990, Von et al 1991). For instance, chronic low back pain
patients cost over USD$40 billion annually in direct medical treatment and costs
associated with disability (Andersson 1999). Moreover, the cost related to the loss of
productivity due to time off work, loss of skilled workers and reduced work efficiency
has profound impact on the social economy (Blyth et al 2003). It is estimated that about
6
61.2 billion dollars was lost from loss of productivity due to pain conditions in the US
workforce per year (Stewart et al 2003).
One of the most common chronic pain syndromes is myofascial pain (Ashbum et al
1999).
2.3 Myofascial Pain
2.3.1 Definitions
Myofascial pain or myofascial pain syndrome is a localized muscle pain syndrome that is
classified as a common musculoskeletal disorder (Gerwin 2001). It is characterized by
muscles in a contracted state with increased tone and stiffness, and that contain
myofascial trigger points (Simons et al 1999). Myofascial trigger point (TrP) was defined
by Simons (1995, 1999) as self-sustaining hyperirritable spot located in taut band
(contracted group of muscle fibers) of skeletal muscle or its associated fascia with zone
of tenderness. Direct compression or palpation of TrP provokes radiating and aching type
of pain into localized referred area namely referred pain (Wheeler 2004). When needle
or mechanical stimuli is applied on TrP, it often elicits a local twitch response (LTR)
which is a sharp contraction of muscle fibers, and that creates a strong patients’ reaction
or “jump sign” (Gerwin 2001, Wheeler 2001). TrP can be divided into active or latent.
Both active and latent TrP share similar characteristics as mentioned but latent TrP is only
painful when palpated (Simons 1995).
2.3.2 Epidemiology
The prevalence of myofascial pain in the general population is unknown. However, it is
extremely common and affects many individual’s life at one time (Mense et al 2001). A
study of 200 young asymptomatic adults found that 54% males and 45% females had
focal tenderness presenting latent TrP (Sola et al 1955). Other studies showed that
myofascial pain is highly prevalent among patients with regional pain (localized pain)
complaints. Fishbain et al. (1986) showed that among 283 chronic pain patients admitted
to a pain center 85% had myofascial pain with TrP. More recently, a study by Gerwin
(1995) showed that 74% of 96 patients with musculoskeletal pain seen by a neurologist in
7
a community pain medical center presented myofascial pain symptoms while another
study (Lin et al 1997) found that 94.5% of 109 patients with musculoskeletal disorders
were myofascial pain.
Myofascial pain is frequently associated with chronic head, neck and back pain (Simons
1988). In a study of 164 patients referred to a pain clinic with chronic head and neck pain,
55% were found to have myofascial pain (Friction et al 1985). In another study, Weiner
(2006) showed that among 131 chronic low back pain patients, 95.5% of them had
myofascial pain. Low back pain is considered to be frequently associated with myofascial
pain (Borg-Stein et al 2002, Simons 1988, Weiner 2006).
2.3.3 Symptoms and Diagnosis
Diagnosis of myofascial pain is difficult because there is no objective assessment.
Trigger point (TrP) identification relies exclusively on the quality of patients’
examination by palpation. Identifying taut band with tenderness is the key to locate
contracted muscle fibers and subsequently TrP (Gerwin 2001). Patients with TrP present
clinical symptoms such as localized or regional deep aching sensations, hypersensitivity,
allodynia (pain evoked by a non-painful stimulus), palpable nodules or taut bands with
local tenderness, muscle weakness and decreased range of motion at sites of TrP
(Borg-Stein et al 2002, Gerwin 2001, Harden et al 2000, Hong et al 1998, Simons et al
1999). Other functional complaints include decreased work tolerance, impaired muscle
coordination, stiff joints and fatigue (Friction et al 1985). Myofascial pain is usually not
only localized, but also referred to a particular distance on compression of taut band.
Referred pain pattern varies from muscles to muscles. Simons (1993) has estimated that
referral patterns in 20% of muscles is in an upwards and downwards direction in response
to the triggered muscle; 48% muscles have a downwards direction; in 5% of muscles it is
in upwards direction; 10% is locally around the TrP; 17% is locally around and
downwards.
Apart from abnormal sensation and motor limitations, signs of autonomic dysfunction
8
with increased sympathetic activity, including abnormal sweating (sudomotor reflex),
decrease in skin temperature (vasomotor reflex), local skin oedema, goosebumps
(pilomotor reflex) and some trophic changes such as dermatomal hair loss, cracking nails
are found in most of the myofascial pain cases (Baldry 2001, Borg-Stein et al 2002, Gunn,
2007, Shah 2008).
2.3.4 Perpetuating Factors and Types of Myofascial Pain
Main contributing factors of myofascial pain are direct or indirect trauma, exposure to
cumulative and repetitive strain, overloading or overuse of muscle and postural
dysfunction (Borg-Stein et al 2002, Wheeler 2001). When myofascial pain is due to these
mechanical causes it is called “primary myofascial pain”. Common primary myofascial
pain syndromes include myogenic (tension-type) headache, neck pain, shoulder pain, low
back pain, piriformis syndrome, leg pain, knee pain and ankle pain (Gunn 1997, Baldry
2001, Gerwin 2001).
Other non-mechanical causes such as chronic infection, visceral diseases, peripheral
neuropathy (nerve lesion or dysfunction in peripheral nervous system), compression of
nerve root (radiculopathy) and vitamin deficiency are responsible for the development of
“secondary myofascial pain” because myofascial pain often occurs in conjunction with
other conditions (Backonja et al 1998). Examples of secondary myofascial pain include
temporomandibular joint dysfunction, carpal tunnel syndrome, impingement syndrome,
rotator cuff tear, visceral pain syndromes, radicular pain, complex regional pain
syndrome and spondylosis (Gerwin 2001).
2.3.5 Pathophysiology
Pathophysiology of myofascial pain has been described in books such as “Myofascial
pain and dysfunction: the trigger point manual” (Simons et al 1999), “Muscle pain:
understanding its nature, diagnosis and treatment” (Mense et al 2001) and “Myofascial
pain and fibromyalgia syndromes: a clinical guide to diagnosis and management” (Baldry
9
2001). Below gives summaries regarding the pathophysiology of primary and secondary
myofascial pain.
2.3.5.1 Primary Myofascial Pain
Research investigating myofascial pain shows that direct injury and mechanical stress on
muscle are primary causes for myofascial pain (Baldry 2001). Trauma or abnormal stress
causes affected muscle fibers to release intracellular calcium excessively. This abnormal
increase of calcium induces uncontrolled muscle fibers shortening (contracted) activity,
local circulation impairment and increased metabolism, resulting in the formation of
muscle contracture or taut band and the activation of TrP (Hong et al 1998). These muscle
tension abnormalities cause local ischemia and the shortened muscles release endogenous
substances such as bradykinin, prostaglandins and serotonin. These endogenous
substances are muscle nociceptor activating substances which activate muscle
nociceptors and subsequently cause deep muscle aching pain, muscle tenderness, muscle
weakness and decrease range of motions (Mense 2003, Mense et al 2001, Galluzzi 2007).
Furthermore, sensitized muscle nociceptor endings release neuropeptides such as
substance P and calcitonin gene-related peptide (CGRP) which lead to a cascade of
events including the release of histamine, bradykinin, prostaglandins and serotonin. This
cumulative effect creates local edema in muscle tissue (Shah 2008). Furthermore, this
rapid and intense discharge of sensory fibers (sensory afferent barrage) activate
sympathetic preganglionic neurons on reaching the spinal cord and thus causes
noradrenergic postganglionic neurons in sympathetic chain become activated. As a result,
sympathetic efferent activity is being increased and causes the release of norepinephrine
which is responsible for the autonomic phenomena (Jay 1995, Baldry 2001). Besides,
studies show that activation of sympathetic preganglionic neurons is responsible for pain
generation (Janig 1995, Janig et al 2001, 2003) and may directly involves inflammatory
pain through secretion of nerve growth factor (NGF) driving local inflammation
(Andreev at al 1995, Woolf et al 1996).
Apart from peripheral muscle nociceptor sensitization, central sensitization at spinal cord
10
dorsal horn may also responsible for myofascial pain mechanism (Hong et al 1998).
When peripheral nociceptors are sensitized by injured muscle as described above, the
high-threshold Group IV (C) afferents will fire at lower threshold. This lowering of the
activation threshold fires more readily and thus induces central sensitization at dorsal
horn (Hoheisel et al 1993). This neuroplastic change causes allyodnia and also induces
deep somatic afferents ramify and converge at synaptic connections with post-synaptic
(second-order) neurons at dorsal horn. And this explains the phenomenon of referred pain
to adjacent muscles due to the expansion of receptive field (Vecchiet et al 1999, Bahr et
al 1981). Central sensitization can also activate the release of substance P and
N-methyl-D-aspartate (NMDA) channel which further enhances the synaptic connections
at dorsal horn. This may account for the persistent pain when TrP is once activated (Shah
2008).
2.3.5.2 Secondary Myofascial pain
Myofascial pain can also be secondary to visceral diseases because visceral afferent
synapse and somatic afferents both terminate at Lamina I and V at specific segment of
spinal cord. This dual innervation results in convergence of somatic and visceral input
(Stephen 2006). Therefore, nociceptive input from internal organs appears to augment the
excitation of transmission neurons primarily concerned with receiving inputs from
muscle nociceptors and sensitizes muscle efferent fibers, causing pain and tenderness
perceived in muscles associated with the affected visceral organs (Baldry 2001,
Graven-Nielsen 2006).
Other causes of peripheral neuropathy, such as nerve compression, chronic infections,
and tumor may cause nerve lesion or dysfunction which is also responsible for the
development of secondary myofascial pain (Backonja 2003, Backonja et al 1998,
Dworkin 2002, Hansson et al 2001, Latov 2007, Wheeler 2004). Nerve lesion or
dysfunction causes hypersensitivity in striated muscle of neuropathic origin (i.e.
peripheral neuropathic pain) which triggers activation of TrP and subsequently the
pathological mechanism of myofascial pain (Gerwin 2001). We will see below that
11
intramuscular stimulation (IMS) bases its intervention strategy on a pathophysiological
model that considers most chronic myofascial pain syndromes to be secondary to the
compression of nerve roots (Gerwin 2001, Gunn 1997).
2.3.6 Treatments
Treatments for myofascial pain are diverse. Conventional systemic treatment for
myofascial pain includes non-steroid anti-inflammatory drugs (NSAIDs), opioid,
antidepressants, anticonvulsants, muscle relaxants (Wheeler 2004, Borg-Stein et al 2002).
However, because of limited long-term efficacy and safety of conventional treatments,
alternative treatments such as dry needling (including acupuncture and intramuscular
stimulation (IMS)), transcutaneous electrical nerve stimulation (TENS), low level laser
therapy (LLLT), massage and exercises are also widely used to treat chronic myofascial
pain patients (Baldry 2002, Cummings 2007, Han et al 1997).
2.3.6.1 Conventional systemic treatment
2.3.6.1.1 Oral medication
Non-steroid anti-inflammatory drugs (NSAIDs) such as ibuprofen, indomethacin and
diclofenac are commonly used as first line medications in treating mild myofascial pain
patients because of the safety and low cost (Yap 2007). A recent review of evidence from
American Pain Society stated that NSAIDs when compared to placebo showed
significant difference in alleviating chronic low back pain a week after treatment (Chou et
al 2007). However, long term use of NSAIDs is not recommended due to frequent
occurrence of renal and gastrointestinal adverse effects (Wheeler et al 1995, Argoff et al
1998).
Common muscle relaxants for myofascial pain include cyclobenzaprine, carisoprodol,
methocarbamol, chlorzoxazone, metaxalone and tizanidine (Wheeler2004). Clinical trials
have demonstrated that patients with acute neck and low back disorders had a significant
decrease of muscle spasm severity and pain levels (Abrus et al 1990, Berry et al 1988,
Fryda-Kaurimsky et al 1981) but evidence for chronic myofasical pain is still limited
(Moulin 2001, Aker et al 1996). Adverse effects such as sedation and muscle weakness
12
are observed (Wheeler2004).
Antidepressants such as amitriptyline and despiramine are found to be effective in
particular for chronic tension-type headache and back pain (Argoff et al 1998, Bendtsen
et al 2000, Brown et al 1978). A systematic review of antidepressants against placebo for
chronic back pain (9 trials) found a standardized mean difference (SMD, difference in
means divided by a standard deviation) of 0.41 (CI, 0.22-0.61) for pain relief (Salerno et
al 2002). Adverse events associated with antidepressants include sleep disturbance,
cardiac conduction block, dizziness, constipation and sexual dysfunction (Settle 1998).
Anticonvulsant is a common type of neuropathic analgesics which treat neuropathic pain.
As secondary myofascial pain is usually induced by peripheral neuropathy,
anticonvulsants such as gabapentin, venlafaxine and benzodiazepines are also used in
treating myofascial pain patients. A Cochrane review (2 high-quality trials) found
tetrazepam to be associated with a greater likelihood of pain relief (RR, 0.71 [CI,
0.54-0.93]) and global improvement (RR, 0.63 [CI, 0.42-0.97]) compared to placebo in
treating chronic low back pain, after 10 to 14 days (Cochrane Back Review Group 2003).
Side effects of anticonvulsants reported include depression, drowsiness, dizziness,
constipation nausea and ataxia (Wiffen et al 2005).
Opioids like tramadol are commonly used for treating severe myofascial pain especially
in lower back (Bord-Stein et al 2002). A Cochrane review of opioids (3 high quality trials)
showed that tramadol was more effective than placebo to relieve chronic low back pain
with SMD 0.71 (95% CI 0.39-1.02) and improve function, SMD 0.17 (95% CI 0.04-0.30)
(Deshpande et al 2007). Beside severe constipation, long term usage of opioids may lead
to the development of aberrant behaviour such as drug abuse and addiction (Argoff et al
1998) and can contribute to prolonged work disability (Henderson 1991, Swartz et al
2000).
2.3.6.1.2 Therapeutic Trigger Point Injection
Therapeutic trigger point injections have also been used empirically in myofascial pain
13
patients. The injections are directed at TrP within the target muscle to block or inhibit
afferent and efferent neural pathways to induce muscular elongation, and thus reduce the
pain (Wheeler 2004). Common types of TrP injections include local anesthetic and
botulinum toxin (Baldry 2002, Borg-Stein et al 2002, Wheeler 2004).
Local Anesthetic Trigger Point Injection
It has been common practice to inject local anesthetic into TrP to decrease pain. Common
local anesthetics used include bupivacaine, lidocaine, mepivacaine, procaine and
etidocaine (Wheeler 2004). Local anesthetics are compounds that, when applied to nerve
tissue, produce a reversible loss of sensation. They interfere with the conduction
process of nervous tissue by preventing the voltage dependent increase in sodium
conductance and thus, block the initiation and propagation of action potentials (Catterall
1987). Double blind RCTs have shown that the effect of local anesthetics were not
superior to that of saline. Tschopp (1996) in a study of 107 patients showed that there was
no significant difference among groups receiving bupivacaine 0.25% (% of residual pain:
21.3 ± 6.3 %), lignocaine 1% (33.1 ± 5.7 %) or saline 0.9% (28.8 ± 5.8 %) with respect to
reduction of pain after 1-week follow-up. Similarly, in a 4-day trial of 53 patients, Frost
(1980) showed that mepivacaine 0.5% injection (75% improved) did not provide any
benefit over saline injection (68% improved) in reducing pain. Two other high quality
trials showed that dry needling and local anesthetic injections had comparable effects in
reducing pain. In a trial (n=30), McMillan (1997) showed that pain intensity and
unpleasantness scores decreased significantly at the end of treatment in all groups (I:
procaine + simulated dry needling; II: dry needling + simulated local anesthetic; III:
simulated local anesthetic + simulated dry needling). There were no statistically
significant between-group differences in pain pressure thresholds and pain scores after 3
weeks of treatment (VAS I: baseline=39±24 follow-up=28±32; II: baseline=37±18
follow-up=25±25. III: baseline=34±25 follow-up=19±20). Garvey (1989) found in a trial
(n=63) comparing 4 groups (I: lidocaine 1%; II: lidocaine 1% + corticosteroid; III: dry
needling; IV: acupressure + vapour coolant spray), there was no significant pain relief
difference among the groups at 2-weeks follow-up (I: 31% improved; II: 36% improved;
III: 55% improved; IV: 50% improved). Most of these trials are underpowered to show
14
any effect and of poor quality; despite these two limitations, it seems that the effect of
injecting local anesthetic does not improve much when compared to dry needling which
treats the same TrP.
Botulinum Toxin Trigger Point Injection
Botulinum toxin is a potent neurotoxin which causes flaccid muscle paralysis by blocking
acetylcholine (a chemical that causes muscle contraction) release at the neuromuscular
junction (Ho et al 2007). A systematic review included 5 studies comparing botulinum
toxin A and saline injection where 4 trials (n=246) showed insignificant difference
between both groups in reducing myofascial pain while 1 study (n=26) found that
botulinum toxin A group (change in VAS=-2) had greater reduction in pain when
compared to saline group (change in VAS=1.5) in 4 weeks (Ho et al 2007). A small trial
(n=18) showed that botulinum toxin A (decrease in VAS = 2.705 ± 3.31) and bupivacaine
0.5% (decrease in VAS = 2.0 ± 2.03) had equivalent effect in reducing pain in MPS
(Graboski et al 2005).
The above clinical trials are characterized by small sample size and poor quality. They
show that trigger point injections, regardless the types of drugs, had benefits in reducing
myofascial pain but are not superior to that of saline injection and dry needling (Tschopp
1996, McMillan 1997, Garvey 1989, Graboski et al 2005, Porta 2000). “Needling effect”
appears to be the key factor to reduce the pain and this would explain why all patients
show a significant pain reduction after treatment – with or without injection and whatever
the injection is. Overall, conventional drugs injections have been shown to have a
short-term positive effect in alleviating myofascial pain. However, (a) long-term efficacy
of these drugs remains unclear and (b) the effect seem to be similar of what is observed
with simple dry needling. Adverse events reported in therapeutic injection therapy
included dizziness, nervousness, insomnia, regional weakness, soreness and dry mouth
(Dreyer 2000).
15
2.3.6.2 Alternative Treatments
2.3.6.2.1 Exercises
Stretching exercises serve as the basis of exercise treatment of myofascial pain because
daily stretching muscles address the release of muscle tightness and shortening and thus
permit gradual restoration of normal activity (Borg-Stein et al 2002). Other forms of
exercises like strengthening exercises (repetitions of specific muscle contraction) and
aerobic exercises (such as walking and cycling) are also recommended in rehabilitation
program to prevent overloading muscles and recurrence of myofascial pain
(Graff-Radford et al 1987). A controlled study of 20 patients with chronic myofascial
pain in temporomandibular region showed that active and passive jaw movement
exercises and correction of body posture were useful in reducing pain and increasing
range of motion (Nicolakis et al 2002). Meta-analysis of a Cochrane review (23 trials of
chronic pain patients out of 43 trials) showed that the pooled weighted mean
improvement was 10.2 (95% CI: 1.31 to 19.09) for exercise therapy compared to no
treatment, and 5.93 (95% CI: 2.21 to 9.65) compared to other conservative treatments
(van Tulder et al 2000). However, most of the trials were low in quality due to inadequate
blinding.
2.3.6.2.2 Massage
Massage is a soft tissue manipulation using hands with pressure on any part of body.
There are many different kinds of massage, for instance, deep tissue or trigger point
massage applies pressure on taut band creating reflex relaxation; Swedish massage uses
strokes flowing on the body which creates deep circular movement, friction and vibration
to reduce muscle stiffness and promote blood circulation (NCCAM 2009). Massage is
thought to offer symptomatic relief of pain through physical and mental relaxation (Ernst
1999). The manipulations and pressure of massage may break down subcutaneous
adhesions and prevent fibrosis and promote circulation of blood and lymph (Donnelly et
al 2002) Research has suggested that massage stimulation might help to block pain
signals sent to the brain (Melzack et al 1965). It is also suggested that massage might
stimulate parasympathetic activity which promote reduction of anxiety and depression
and autonomic dysfunction including odema (Field 1998, Ferrell-Tony et al 1993). A
16
systematic review (5 trials with chronic low back pain) showed the possible benefits of
massage therapy in relieving chronic low back pain (Furlan AD et al 2008).
Meta-analysis was not available in the review due to heterogeneity across trials in terms
of difference in comparative treatments and outcome measurements. One large study with
long term follow-up (n=172; Cherkin 2001) showed that, taut band or TrP massage was
superior to acupuncture in its effect on pain (symptoms scale 3.08 vs 4.74, p = 0.002) and
function (dysfunction scale 6.29 vs 8.21, p = 0.05) at 52 weeks after randomization.
Another large study (n=100; Geisser 2005) showed that massage therapy for myofascial
pain (muscle energy technique that promotes muscle relaxation by activating the golgi
organ reflex) combined with exercises appears to be beneficial in treating chronic
low-back pain when compared to sham massage (no muscle energy technique) plus
exercises (change in VAS score was -2.05 vs -0.38). Although massage was found to be
beneficial in treating chronic low back pain in this review, most of the trials were prone to
biases because of the lack of blinding and unclear concealment of allocation (Furlan AD et
al 2008).
2.3.6.2.3 TENS and LLLT
Transcutaneous electrical nerve stimulation (TENS) and low level laser therapy (LLLT)
are both non-invasive and safe devices for treating myofascial pain. TENS is an electrical
stimulation applied on surface of skin to relieve pain. Stimulation parameters for TENS
vary from trial to trial. In general, high frequency (40-150Hz), low intensity current
amplitude (10-30mA) and short pulse duration (50 microseconds) are usually enough to
produce a motor contraction (Sluka et al 2003, eMedicine 2007). The effect of TENS in
relieving pain is still controversial. For instance, in chronic low back pain, a Cochrane
review (2 trials) showed contradictory results: positive in one study but no effect in the
other (Khadilkar et al 2005). For chronic neck pain, a randomized controlled trial (n=280;
Chiu et al 2005) showed that TENS was more effective in relieving pain than placebo but
not superior to exercises (change in NRS TENS: 0.38±0.60; exercises: 0.39±0.62; control:
0.23±0.63).
17
LLLT is a red or infra red beam laser with wavelength from 632nm-904nm and power
from 15mW to 100mW (Mester et al 1985, Emshoff et al 2008). A Cochrane review
included 4 trials with chronic low back pain patients (Yousefi-Nooraie et al 2008). Of
which two studies (n=61; Djavid 2007 , Klein 1990) comparing LLLT plus exercises
versus sham laser plus exercises showed a pooled result of weighted mean difference
(WMD) was -6.38 in pain relief (95%CI: -15.68 to 2.91) at short-term follow-up
(Yousefi-Nooraie et al 2008). Another study in the review (n=71; Soriano 1998) showed
that LLLT (44.7% of patients had excellent pain relief) was superior to sham laser (15.2%)
in relieving chronic low back pain at 6 months follow-up. A recent double-blind
randomized controlled trial (Gur A et al 2004) of 60 chronic myofascial neck pain
patients, the improvement of pain in LLLT (63% of patient had pain relief) is statistically
better than that in placebo group (19%).
2.3.6.2.4 Dry Needling
Dry needling is the use of solid and fine needle for therapy. In pain management, needles
are deeply inserted into muscles to alleviate pain. There are two main types of dry
needling techniques to treat chronic myofascial pain. One is traditional Chinese
acupuncture which targets at points of meridians. Another type is dry needling of trigger
point which targets at points of palpable tenderness in contracted muscle. Dry needling of
TrP can be further divided into two techniques: Ah-Shi acupuncture and intramuscular
stimulation (IMS).
Traditional Chinese acupuncture is a dry needling technique that targets on classic
acupuncture points which emphasize a smooth flow of Qi (vital energy) and homeostasis
in human body. It has been practiced in China for thousands of years in reducing chronic
pain and started to draw attention to western countries in the past decades. Classic
acupuncture points or acupoints are points located along meridians of energy which
connect organs and different parts of body. While another class of acupuncture, Ah-Shi
acupuncture, targets Ah-Shi points which are defined as points of palpable tenderness
located in muscle contracture where the definition corresponds to TrP (Birch 2003, Hong
2000, Shah 2008, Mense et al 2001). Ah-Shi acupuncture is thus a technique of TrP dry
18
needling.
Intramuscular stimulation (IMS), similar to Ah-Shi acupuncture, is a form of dry needling
technique that specifically targets myofascial TrP. It is a standardized technique which
has its unique treatment strategy and theory behind (Gunn 2007). IMS theory is based on
the fact that TrP and taut band at limbs and trunk are closely associated with the
segmental distribution of lumbar radiculopathy at the back (Gunn 1997). It is believed
that any nerve root lesion or dysfunction (peripheral neuropathy) at spine levels will lead
to hypersensitive to the innervated striated muscle of neuropathic origin, creating taut
band and myofascial pain (Cannon et al 1949). According to this vision, IMS model
assumes chronic myofasical pain is mostly secondary to initial peripheral neuropathic
lesion (i.e. radiculopathy in most instances). Therefore, IMS is a broader approach of TrP
needling when compared to Ah-Shi acupuncture. IMS targets not only contracted limb
and trunk muscles, but also the associated segments of paraspinal muscles (semispinalis,
rotators, multifidus and spinalis) at spine levels with the objective to remove the source
of pain (Gunn 1989, Gunn 1997) (Appendix A). This theory is interesting, but it has
never been documented by any experiments.
Several hypotheses of dry needling mechanism have been suggested. First of all, recent
studies proposed that inserting needles into TrP might create a local twitch response (LTR)
that evokes transient contractions of muscle fibers and sensitizes reflex motor efferent
activity or golgi organs (proprioceptive sensory receptor organ that measures tension of
muscle contraction and causes reflex reaction) causing muscle relaxation to occur (Baldry
2001, Longhurst 2004). By removing muscle contraction, excessive release of calcium
and endogenous substances in muscles may be terminated, and subsequently discontinue
the peripheral sensitization (Shah 2008). Because of the high spatial correspondence
between classic acupuncture points and TrP (Melzack 1977), needling at acupuncture
points might also produces LTR where scholars regarded this phenomenon as “De Qi”. In
addition, recent animal studies documented that acupuncture needles activate
proprioceptive Aβfibers which inhibit the input of small nociceptive C fibers according to
Gate Control Theory (Moffet 2006, Abram 2006). Besides, studies also proposed that
19
needle insertion may stimulate Aδfibers which causes interneuron activation in the dorsal
horn and the release of endogenous opioids and neurotransmitters (serotonine,
gama-aminobutyric acid and acetylcholine), inhibiting intra-spinal transmission of C fiber
input (Cheung et al 2001, Moffet 2006). Another hypothesis is that acupuncture can
modulate the sympathetic outflow and reduce the sympathoexcitatory reflex response (Li
et al 1998, 2001, Dai et al 1992, Tjen-A-Looi et al 2003) with decrease of the
inflammatory reaction and subsequently pain (Longhurst 2004). Some studies also
hypothesized that acupuncture can influence electromagnetic field in the body and thus
alter the chemical neurotransimitters which inhibit central sensitization, reversing
neuroplasticity in the nervous system (Audette et al 2004, Shupak et al 2004).
Studies have been carried out for evaluating the effect of dry needling in treating chronic
myofascial pain has been identified. For traditional acupuncture, studies applied needles
at classic acupuncture points mainly on meridians BL, GB and KI with insertion varied
from 0.5 to 2 inches. A Cochrane systematic review (Furlan et al 2005) gave evidence
supporting the short-term (3 months or less) pain relief and functional improvement of
acupuncture in chronic low back pain patients, compared to no treatment or sham therapy.
In the review, the pooled analysis of two low quality trials (Coan et al 1980, Thomas et al
1994) showed that acupuncture was more effective than no treatment for short term pain
relief, with a standardized mean difference (SMD: mean difference divided by standard
deviation) -0.73 (95% CI: -1.19, -0.28). Acupuncture was also shown to be more
effective than sham therapy in terms of short term pain relief, with a weighted mean
difference (WMD: sum of the differences weighted by individual variances) -1.78 (95%
CI: -2.55, -1.07) from two high quality trials (Carlsson et al 2001, Molsberger et al 2002).
However, results for intermediate-term (3 months to 1 year) pain relief did not show
acupuncture was better than sham therapy. A pooled result from two high quality trials
(Carlsson et al 2001, Leibing et al 2002) found that acupuncture was not significantly
better than sham therapy in terms of intermediate-term pain relief, with a WMD -0.57
(95% CI: -1.47 to 0.33). Similar result was obtained from two recent large studies by
Haake et al (2007) and Brinkhaus et al (2006). Haake et al (2007) showed that the mean
difference between acupuncture and sham (needling at non-acupoints) was -3.4 (95% CI:
20
-10.3, 3.7) at 6-months follow-up. While Brinkhaus et al (2006) found the mean
difference between acupuncture and superficial needling was -0.6 (95% CI: -1.4, 0.3) at
12-months follow-up. Both studies showed no significant difference in pain relief
between acupuncture and sham acupuncture in intermediate term.
For dry needling of TrP or Ah-Shi acupuncture, six trials were identified and needles
were inserted approximately 0.5-1 inch into trigger points according to different trials.
Most of them were of poor methodological quality and limited to small sample size. In a
trial of 30 patients with chronic myofascial pain in jaw muscles, McMillan (1997)
showed that pain intensity and unpleasantness scores decreased significantly at the end of
treatment in all groups (procaine 1% vs dry needling vs sham dry needling). However,
there was no statistically significant between-group difference in pain scores after 3
weeks of treatment. One trial showed that the effect of TrP needling and sham laser
acupuncture in alleviating chronic neck pain were comparable immediately after
treatment (Irnich et al 2002) with mean difference of 1.7 (95% CI: 1.0, 2.5). Another
chronic pain study (Itoh et al 2007) found that TrP needling was superior to sham
needling at 13-week follow-up. Ga & Choi et al (2007) showed that acupuncture had
comparable effects to 0.5% lidocaine injection at 1-month follow-up in elderly MPS
patients in upper trapezius muscle. Different results were found in 2 other studies. A trial
of 29 patients with chronic cervical, back or shoulder MPS by Kamanli (2005) showed
that 0.5% lidocaine or botulinum toxin A were more effective in reducing pain than dry
needling at 1 month follow-up. Another trial without blinding patients (Hong 1994) also
showed that lidocaine 0.5% injection had a greater pain relief at 2 weeks after treatment
when compared to dry needling. The two chronic neck pain studies as described above
also compared the effect of alleviating chronic pain between classic acupuncture and dry
needling of TrP. However, the results were controversial (Irnich et al 2002, Itoh et al
2007).
Two studies were identified for the evaluation of IMS. Needles were inserted about 1-2
inches into muscle of taut bands and paraspinal muscles at the associated spinal segments.
Both of them were of low quality. Ga & Koh et al (2007) showed that among 43 patients
21
with chronic myofascial pain in upper trapezius muscle, IMS was equivalent in reducing
pain intensity to lidocaine 0.5% injection at 1-month follow-up. Another study by Gunn
(1980) involved 53 patients with chronic low back pain without blinding patients. Both
groups followed a standard regimen of physiotherapy, remedial exercises and
occupational therapy while subjects in treatment groups also received IMS twice a week.
In the IMS treatment group 62% of patients returned to their original work and 34%
shifted to a lighter employment while in the control group only 15% of patients returned
to their original work and half of these worked in a lighter employment.
All in all, among these dry needling techniques, more RCTs were conducted assessing the
effect of traditional Chinese acupuncture when compared to the other two. The existing
evidence shows that acupuncture is better than sham therapy in reducing chronic low
back pain only in the short-term, there is not enough evidence showing acupuncture is
superior to sham regarding intermediate and long-term benefits. For dry needling of TrP,
trials were mainly small in size and with poor methodological quality. It seemed that dry
needling exhibited similar effect in alleviating chronic myofascial pain compared to
anesthetic injections (Cummings et al 2001), but the effect of TrP needling over sham
needling was not well documented. We found two studies comparing classic acupuncture
and TrP needling techniques with controversial results. Regarding IMS, although the two
identified studies showed favourable outcomes towards IMS, they were of poor quality
and small sample size. Despite the lack of solid evidence, the IMS technique has been
used widely: hundreds of practitioners have been trained and practice worldwide.
Testimonials and donations from patients speak to the positive effects of IMS but no solid
clinical evidence is currently available supporting the effect.
22
CHAPTER 3: Rationale, Objectives and Hypothesis
3.1 Rationale
Although there are different kinds of treatments available for myofascial pain, chronic
myofascial pain patients are still under-treated (Breivik 2006, Robinson 2007). A survey
done by the American Pain Society in 1999 revealed that more than four out of ten people
suffering moderate to severe pain were unable to find adequate pain relief (American
Pain Society 1999). In this context, complementary and alternative treatments (CAM) are
frequently used by patients. It is therefore important to evaluate the effect of alternative
treatments so as to better inform the public regarding their safety and effectiveness in
alleviating chronic pain. Among a large range of alternative treatments, Intramuscular
Stimulation (IMS) lacks solid clinical evidence and seems interesting. This is why my
thesis focused on the evaluation of IMS technique in improving chronic myofascial pain.
The randomized controlled trial (RCT) is the gold standard for assessing the efficacy of a
treatment. However, several observational studies have to be conducted before to assess
whether there is a treatment effect and the associated effect size so as to better calculate
the sample size needed for the RCT. Also, these studies are useful to standardize data
collection in order to reduce any recording bias. Furthermore, before conducting a
multi-practitioners study, it is important to standardize the practice and to ensure all
practitioners involved examine and treat patients in the same way. With these objectives
in mind, preliminary studies including two chart reviews and one inter-rater-reliability
test have been conducted in the preparatory phase of setting up a RCT to evaluate the
effect of IMS.
3.2 Objectives and Hypothesis
General Objective:
The thesis’ goal was conducting three preliminary studies to generate useful information
that would help deciding to conduct (or not) a RCT and designing this trial. Each study
has specific objectives and hypotheses.
23
Study 1: First Chart Review
The overall objective of this study was to gather useful information regarding the
effectiveness of IMS to justify the conduct of RCT. Specific objectives were 1) to
describe the patients’ population at one IMS clinic; 2) to document the IMS effect
(decrease in pain) in treating chronic myofascial pain. We hypothesized that the success
rate of IMS (pain intensity reduced by at least 1 unit on 0-10 point scale) would be at
least 50% in patients with myofascial pain for 3 months or more.
Study 2: Second Chart Review
Because of missing information during the first chart review, the clinic modified its chart
recording process using standard forms. The overall objective of this second chart review
was to gather useful information for the design of RCT to assess the effectiveness of IMS.
Specific objectives were 1) to access the effect size of IMS in pain improvement; 2) to
assess the effectiveness of IMS in improving disability, quality of life and to assess
patients’ satisfaction towards treatment. We hypothesized that the success rate of pain
improvement (pain intensity reduced by at least 1 unit 0-10 point scale) would be at least
50%.
Study 3: Inter-rater Reliability Test
The primary objective of this study was to test the agreement among IMS practitioners in
identifying number of tender taut bands in spinous muscles along the spine and in
extremity muscles in different parts of body. Secondary objective was to test the
consistency of IMS practitioners in identifying taut bands in each muscle and recording
the signs of autonomic dysfunction. We hypothesized that the agreement in identifying
number of tender taut bands in different regions would be at least 0.6 (Intra-class
correlation coefficient) and the kappa values of identifying taut band in each muscle level
would be at least 0.6.
24
CHAPTER 4: Study 1-Documentation of the Effect of Intramuscular Stimulation to
Treat Chronic Myofascial Pain: A Chart Review
4.1 Introduction
With the objective to test the feasibility of conducting a randomized controlled trial (RCT)
to assess the effect of Intramuscular Stimulation (IMS) in treating chronic pain a chart
review was conducted in an IMS clinic in Vancouver to gather preliminary information
regarding patients’ population characteristics and the treatment effect. This information
is essential to the design of a RCT in terms of recruitment and sample size estimation.
4.2 Methods
4.2.1 Study Design
The design is observational. Chart review was conducted in two phases. Phase 1 was a
systematic review of randomly selected patients’ charts at an IMS clinic in Vancouver.
Phase 2 was a telephone interview of selected patients to gather their subjective opinion
regarding long term effects and satisfaction of IMS treatment in alleviating their chronic
pain.
4.2.2 Study Population
Patients who suffered from chronic (pain persisted at least 3 months) and received their
first treatment between 1st January, 2006 and 31st December, 2006 at the clinic were
eligible for the study regardless of their age, sex and regions of pain. Patients who had
their pain that persisted less than 3 months at the time of first visit were excluded. A total
of 213 patients were identified from the above criteria and 100 patients were then
randomly selected for chart review using computer-generated random number. The same
100 patients were also invited to participate in the second phase of the study, a telephone
interview.
4.2.3 Study Procedure
4.2.3.1 Chart Review
The selected 100 patient’ charts were reviewed systematically by the student. All
necessary chart information including patients’ age, gender, regions of pain, pain onset,
25
number of treatments received, subjective reporting of their pain improvement after
treatment, and practitioners’ comment on patients’ pain control were extracted using
standard data extraction forms. Collected information was reviewed by the Principal
Investigator to assess the quality of data collection.
4.2.3.2 Phone Interview
The same 100 patients were mailed a consent form with a covering letter and a
pre-stamped reply envelope asking for their permissions of telephone interview.
Telephone interviews were conducted within one week after the return of patients’ signed
consent forms. All telephone interviews were carried out by the student. Interviews were
done in a closed and quiet room to ensure confidentiality and interview quality. Interview
content was based on a standardized questionnaire which contained 10 questions in
relation to pain onset, pain complaint, IMS treatment period, pain control after IMS
treatment, persistence of treatment effect, current pain status, overall satisfaction with the
treatment, opinion towards IMS effect in comparison with other treatments and
recommendation of IMS.
4.2.4 Ethics
The study proposal and related materials were approved by UBC Clinical Research
Ethics Board on 8th May, 2008.
4.2.5 Statistical Analysis
Statistical analysis was descriptive and results are presented with 95% confidence
intervals (95% CI). The population treated at the clinic during the period along with
useful chart information such as pain onset, pain complaints, number of treatments
received, degree of pain relief and satisfaction with treatment are described and presented
either as means and standard deviations or as percentages. Telephone interview results
are also described and presented the same way.
26
4.3 Results
4.3.1 Chart Review
4.3.1.1 Population Characteristics
The mean age of the 100 patients was 51.1 (sd = 12.1), most of them (32%) were aged
between 41 and 60 with 45% female. 18% of the population had pain persisted for less
than 1 year (at least 3 months), 15% had pain for 1-3 years, 19% had pain lasted for 4-9
years and 30% of patients had their pain for more than 9 years by the time they received
the first IMS treatment. Of the 100 patients, 12% had one region of pain; 34% had two or
three regions of pain, 46% suffered from four or five regions and 8% had more than five
regions of pain. Nearly 80% of the patients had lower back pain as one of their pain
complaints. Upper back contributed 48%, neck and shoulder pain were 61%, upper limbs
were 25% and lower limbs were 30%.
4.3.1.2 Treatments
Eight different practitioners were responsible for the administration of IMS to these 100
patients. Treatments were usually done on a once or twice a week basis. Number of
treatment sessions varied by individuals, ranged from 1 session to 89 sessions. On
average, patients received 10 sessions of IMS treatments (95% CI= 7.6, 12.9) with a
median of 6 sessions.
4.3.1.3 Practitioners’ Comment on Patients’ Pain Control
Among the 100 charts, 78 charts had records of patients’ pain control. Of these 78
available charts information, 74 charts (95%) reported improvements in pain by
practitioners (Improvement included decreased pain intensity, pain frequency or
increased range of motion). Among the 74 charts that showed improvements, 76% had
lower back pain, 32% had upper back pain, 70% had neck and shoulder pain, 30% had
upper limbs pain, 34% had lower limbs pain. 1 chart (1%) reported no improvement (low
back pain) and 3 other charts (4%) reported worsening. Among these 3 charts, 1 had
lower back pain; 1 had upper and lower back pain; 1 had lower back and lower limbs
pain. Of the 74 improved cases, 42% had records of improvement by the end of second
treatment, 25% had improvements after the third or fourth treatment and the rest started
27
to show improvements after five or more treatments.
4.3.1.4 Subjective Report of Pain Control from Patients
Among the 100 patients, 22 of them had filled out a simple questionnaire consisting of
one question regarding pain control after receiving the treatments. Patients could choose
“much better”, “somewhat better”, “same as before” or “worse” in answering the
questionnaire. Of the 22 patients, 11 patients (50%) stated that they were “much better”
after the treatments, 10 patients (45%) had chosen “somewhat better” and 1 patient (5%)
reported his/her pain as “same as before” after receiving treatments. The answers of those
21 patients who had stated “much better” or “somewhat” better in their questionnaires
were consistent with the charts recorded by practitioners. However, the report of the
patient who stated his/her pain was “same as before” was found to be inconsistent with
practitioners’ record which stated that he/she had improved. Session in which patients
filled out the questionnaire ranged from forth to fifteenth.
4.3.2 Telephone Interview
4.3.2.1 Patients’ Response
Each of the 100 patients received a consent form inviting their participation in a phone
interview but only 18 of them had their signed consents returned. Of these 18 patients, 6
patients were unreachable after 5 attempts of telephone contact. Therefore, only a total of
12 patients (response rate =12%) were successfully involved in phone interviews.
4.3.2.2 Sample Characteristics
In these 12 patients, 8 (67%) had pain for 1 to 4 years while 4 (33%) had pain for over 6
years. All except one had their pain interfere their daily activities. Lower back pain
complaints were found in 10 (83%) patients, 2 (17%) had upper back pain, 2 (17%) had
neck pain, 3 (25%) had shoulder pain, 1 (8%) had upper limbs pain and 3 (25%) had
lower limbs pain.
4.3.2.3 Current Pain Status
Among the 12 respondents, only 1 (8%) had no pain at the time of interview. 6 of them
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(50%) had light pain, 4 (33%) had moderate pain and 1 (8%) still suffered from severe
pain at the time of interview.
4.3.2.4 Treatment Effect
Of the 12 respondents, 6 (50%) commented their pain was greatly alleviated and the IMS
treatment effect was persistent. 1 (8%) commented that though the pain was greatly
alleviated, the treatment effect was importantly decreasing with time. 3 (25%) of them
claimed that their pain was partly alleviated. 1 (8%) reported pain was slightly alleviated
after treatment and 1 (8%) found that the pain did not change. These results were
consistent with what we found in the charts except for the case that reported no change.
In his/her chart, practitioner recorded the pain had decreased and the patient reported
“somewhat better” on the clinic questionnaire at his/her fourteenth visit.
4.3.2.5 Satisfaction and Recommendation
Among the 12 feedbacks from patients, 8 (67%) were highly satisfied with the IMS
treatment and would recommend it to other chronic pain patients. 3 respondents (25%)
were satisfied with the treatment and would recommend others to try the treatment but
not to expect perfect results. One patient (8%) was not satisfied by the treatment and
would not recommend it to others.
4.3.2.6 IMS in Comparison to Other Treatments
Comparing to other ways of controlling pain that respondents had tried on, including
physiotherapy, chiropractics, acupuncture, injections and drugs, 7 out of the 12 patients
(58%) found that IMS was much better than what they had tried. One patient (8%) found
that IMS might be better than other treatments. 3 respondents (25%) suggested that it was
not better and 1 (8%) found that IMS was worse when compared to other treatments.
4.4 Discussion
From chart review, we found that the population treated at IMS clinic was aged from 41
to 60. We also observed that a majority of patients (30%) had their pain for 10 or more
years which corresponds to the fact that (a) many patients remain under-treated with
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currently accessible treatments (American Pain Society 1999) and (b) they consider
alternative treatments after several years of pain. Besides, we found that most patients
suffered from multi-area pain complaints where 80% had lower back pain as one of their
pain complaints. This was consistent with epidemiological studies which showed that low
back pain was one of the most prevalent chronic pain syndromes (Andersson 1999) and
was found to be greatly associated with myofascial pain (Simons 1988, Weiner 2006).
Regarding the IMS treatment effect, we found report of improvement in 95% of the 78
charts that contained IMS practitioners’ records; only 3% of patients got worse. This very
high success rate of a treatment, however, should be interpreted cautiously because 22%
of the data is missing and they correspond to practitioners’ subjective diagnosis. If we
consider that the 22 subjects’ missing information was all from subjects who did not
improve, the success rate would be 74% (a conservative estimate) which is still high,
considering the pain chronicity. We also found personal comment in charts from 22
patients on pain improvement after receiving IMS treatment. Although results were good
with 11 (50%) got much better, 10 (45%) were somewhat better and 1 (5%) had the same
pain as before, the sample size is too small and too selected to act as an evidence
supporting the positive effect of IMS. Also, the patient who claimed that his/her pain was
the same as before on the questionnaire was marked on chart as “showing improvement”
by practitioner. Therefore, the high success rate of IMS treatment as per practitioners’
reports carries some risks of positive interpretation bias.
The telephone interview with patients to collecting subjective patients’ feedback on the
effect of IMS independently to the IMS clinic to prevent the bias was disappointing
because the response rate (12%) was very low. Several reasons may account for this low
response rate. First, our study started in the year 2008 while the treatments were
administered in the year 2006. Some patients had moved to other places as 11 (11%)
envelopes were returned due to wrong address. It is also possible that patients might have
forgotten their treatment experience in IMS clinic. Finally, patients might be unwilling to
receive telephone interviews.
30
Of the 12 respondents, 7 (58%) found their pain was greatly alleviated after receiving
IMS treatment, 4 (33%) had pain partly or slightly alleviated and only 1 (8%) found the
pain did not change. In short, most of the patients involved in phone interview
appreciated the IMS treatment and found that the treatment was at least partially effective
in alleviating their chronic pain. Although telephone interview results were positive, the
response rate is too low to conclude on the effect of IMS.
Overall, the study gave a good picture of the patients’ population at IMS clinic. There
were around 200 new patients with chronic pain every year at the IMS clinic. Most of
them had low back pain, followed by neck and shoulder pain. So the recruitment of
patients to participate in randomized controlled trial (RCT) should not be a problem.
Regarding IMS treatment effect, the results from this study were positive showing good
success rate of the treatment. However, the results were at high risk of bias due to lack of
patients’ subjective comment from charts and low response rate from phone interview.
The success rate from this study was considered not accurate for calculating the sample
size for the RCT. Because of these limitations, we did not compare our results to
published literature; this comparison is part of Chapter 5 (second chart review).
In order to gather more reliable results, we suggested to modify the clinical forms used at
the clinic and to implement a standardized questionnaire for patients to fill out during
their visits. Routine standardized clinical recordings would minimize missing information
and enable better evaluation of IMS treatment.
4.5 Conclusion
The result of this study did not give us enough information regarding the IMS effect in
alleviating chronic myofascial pain. However, this study gave us a general picture of
what kinds of patients were treated at IMS clinic and a preliminary idea about the effect
of IMS. This information was useful to recommend changing the patient’s chart at the
clinic to collect more systematically useful information, coming directly from the
patients.
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CHAPTER 5: Study 2-Documentation of the Effect of Intramuscular Stimulation to
Treat Chronic Myofascial Pain: Second Chart Review
5.1 Introduction
In 2008, in the preparation phase of a randomized controlled trial (RCT), we conducted a
chart review at one intramuscular stimulation (IMS) clinic in Vancouver with the
objective to document the effectiveness of IMS in treating chronic myofascial pain
(Chapter 3). This study had two important limitations: the chart recording process was
not standardized and not consistent between practitioners, and the information was
mostly recorded by the IMS practitioners, therefore prone to a “positive bias”. Secondly,
our attempt to contact patients independently for telephone interview was not successful
with low response rate. Because of these limitations, the IMS clinic decided to change its
routine documentation practice and to collect clinical information in a more systematic
way, using standard questionnaires. The clinical forms for recording clinical findings
were standardized and all patients completed standard questionnaires at their first visit
(baseline), their fourth visit (first follow-up) and eighth visit (second follow-up) to collect
patients’ experience regarding pain, disability, quality of life and overall treatment
satisfaction. The clinic implemented this new patient chart with standard recording on
April 1st, 2009. The second chart review has been carried out on February 1st, 2010
after 10 months of the new data collection process. The general objective of this study
was the same as the first chart review; to determine the feasibility of conducting a RCT
and make appropriate recommendations in the design of RCT if consider feasible. The
primary clinical objective was to assess the success rate of IMS in reducing worst and
average pain intensity. Secondary objective was to assess the effectiveness of IMS in
improving degree of disability, quality of life and to assess patients’ satisfaction towards
treatment.
5.2 Methods
5.2.1 Study Design and Sample Size
It is an observational historical cohort study. All chronic pain patients’ charts with their
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first treatment received at the IMS clinic in Vancouver between April 1st 2009 and
February 1st, 2010 were reviewed. Relevant information from the charts was extracted
using standard forms and transferred to a database for statistical analysis. The target
sample size for this study was the same as the first chart review: 100 subjects to have
80% power to detect a mean difference of 0.8 (SD=2.5) on a 0-10 point pain scale in
Brief Pain Inventory (BPI) between baseline and follow-up in a two-sided paired t-test
with alpha=0.05.
5.2.2 Study Population
Patients with chronic pain (pain that persists at least 3 months) and who had their first
treatment received at the IMS clinic between April 1st 2009 and February 1st, 2010
regardless their age, sex and regions of pain were eligible for this study. Patients with
pain persisting less than 3 months at the time of first visit were excluded.
5.2.3 Chart Review Process
Each chart was systematically reviewed by the student. All useful information including
patients’ age, gender, region of pain, pain intensity, number of IMS treatments received,
degree of disability, quality of life and treatment satisfaction, was extracted and recorded
on standard forms; it was subsequently entered into a computer database. The Principal
Investigator assessed the charts and database from time to time to ensure the quality of
abstraction with the objective to reach a good level of accuracy.
5.2.4 Chart Information
Each chart consisted of an administrative form which contained basic demographic
information (age, gender) and region of pain, and consisted of baseline and follow-up
questionnaires. Baseline questionnaires were completed by patients on the day of their
first IMS treatment. Follow-up questionnaires were completed at fourth and eighth
treatment at the clinic. Baseline questionnaires included 5 questions of 0-10 point scales
measuring pain intensity and the impact of pain on daily function from Brief Pain
Inventory (BPI) and included 10 questions from Oswestry Low-Back Pain Disability
Index (ODI). Similarly, follow-up questionnaires consisted of both questions from BPI
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and ODI, as well as three questions of the Pain Treatment Satisfaction Scale (PTSS)
adapted to measure satisfaction with intervention (Question 55 of PTSS) and the level of
pain relief (Question 56 and 57) (Evans et al 2004). BPI is widely used to assess severity
of pain (worst pain in last week, least pain in last week, average pain, pain right now) and
the impact of pain on daily function (pain has interfered with your general activity, mood,
normal work, relations with others, sleep and enjoyment of life). Questions regarding
severity of pain and impact of pain that we adapted from BPI have been validated for
reliability, consistency and sensitivity among low back pain patients (Cleeland et al 1994,
Keller et al 2004). ODI consists of questions on activities of daily living which include
personal care, lifting, walking, sitting, standing, sleeping, sex life, social life and
traveling where an overall disability index can be computed (overall ODI score
= %100answered questions ofnumber 5
obtained scores of sum×
×): 0-20% minimal disability, 21-40%
moderate disability, 41-60% severe disability, 61-80% crippled (Fairbank et al 1980). It is
one of the most commonly used questionnaires to assess degree of disability for back
pain and has demonstrated good reliability, validity, and responsiveness (Fairbank et al
1980, Kumar et al 2007, Turk et al 2001). PTSS has been validated for both acute and
chronic pain patients’ satisfaction with the study intervention regarding pain control and
improvement in quality of life (Evans et al 2004).
5.2.5 Outcomes
The primary outcome was percentage of “success” in terms of worst and average pain
score on BPI – we kept two outcomes in this exploratory study because the choice
between the two measures of chronic pain is still not clear in the literature. Success was
defined as pain score reduction by at least one unit between follow-up and baseline
because a change of 1 point on BPI scale is regarded as minimally clinically important
changes (Dworkin et al 2008). Secondary outcomes were the change in all BPI outcome
scores; change in overall ODI score and results (in percentage) from PTSS regarding
treatment satisfaction between baseline and follow-up.
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5.2.6 Practitioners
There were four certified IMS practitioners at the clinic responsible for treating the
patients in this study.
5.2.7 Statistical Analysis
This study was descriptive. All results were presented with 95% confidence interval;
when relevant, p-values were calculated (without adjustment for multiple testing). The
primary analysis was based on all the available data. Success was presented in percentage
with 95% confidence interval. Continuous variables were presented as mean difference
with confidence interval; two-way paired t-test was applied for the change in BPI and
ODI outcome scores. Satisfaction towards IMS treatment from PTSS questions was
presented in percentage. A multivariate logistic regression was carried out to identify
predictors of worst pain and average pain changes. Sensitivity analysis was implemented
to present results in different scenarios of missing data at first follow-up: 1) Conservative
estimation was performed for the primary outcome (success/failure) by assuming all the
missing data was treatment failure; 2) Worst and best case imputation were done for
mean changes in BPI and ODI scores by replacing missing values with complete
information based on estimation from the mean and standard deviation of the deteriorated
and improved cases respectively in available data; 3) Last observation carried forward
(LOCF) was also performed assuming the responses were constant over time. Population
characteristics of patients who did not complete questionnaires were presented and
analyzed within the context of future trial development. All statistics were performed
with SAS version 9.1 Windows, SAS Institute Inc., NC, USA.
5.2.8 Long Term Follow-up
Apart from collecting data from usual clinical practice, in early December 2009,
follow-up questionnaires were mailed to patients who were lost to follow-up. However,
among 55 letters that we sent out, we only received 2 respondents (response rate= 4%).
Because of the extremely low response rate, it was not possible to interpret these results
(not presented in this thesis).
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5.2.9 Ethics
The study proposal and related materials were approved by UBC Clinical Research
Ethics Board on October 7th, 2009.
5.3 Results
5.3.1 Population Identification and Follow-up
Figure 5.1 shows the patient flow chart. A total of 155 patients received their first
treatment at the IMS clinic between April 1st 2009 and February 1st, 2010. Of which 15
patients were excluded because they had pain for less than 3 months (acute pain). 21
charts were not included in the study analysis because patients did not want to complete
the questionnaires. The characteristics of these 21 patients are tabulated in Table 5.1.
Finally, a total of 119 patients with baseline questionnaire were included in this study. Of
these 119 patients, 55 (46%) did not complete their first follow-up questionnaire.
Therefore, complete data at first follow-up was available for 64 patients (54%). And 15
patients (13%) completed the second follow-up questionnaire. Among the patients who
did not complete follow-up questionnaires, the main reasons included leaving the clinic
before reaching their follow-up sessions (1st: 32, 58%; 2nd: 17, 35%); censoring before
reaching their fourth or eighth treatment session at the time of study ended (1st: 9, 16%;
2nd: 10, 20%); and refusal to complete questionnaires (1st: 14, 25%; 2nd: 22, 45%).
5.3.2 Population Characteristics
Table 5.2 shows the demographic characteristics of patients who were included in this
study and patients who had completed the first and second follow-up. Of the 119 included
patients, the mean age was 46.6 (sd=12.9), ranged from 16 to 77. Female represented
59% of the population. Most of patients had suffered from pain for 1-3 years (35%) while
23% had pain persisted for more than 10 years. The majority of pain complaints were in
lower back (61%), followed by lower limbs (41%) and neck and shoulder pain (36%).
The mean worst and average pain scores at baseline were 6.93 (sd=2.02) and 5.15
(sd=1.93) respectively. And the mean ODI was 30.41 (sd=18.90) which represented
moderate disability. Similar results were found in patients who had completed the first
follow-up.
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5.3.3 Pain Intensity Change on Brief Pain Inventory (BPI)
Table 5.3 shows changes for worst and average pain at first and second follow-up using
the available data. Regarding worst pain, among 64 patients who completed the first
follow-up, 63% (95% CI: 51%, 75%) had pain improved by at least 1 point (success),
17% (95% CI: 8%, 26%) did not have change in pain score and 20% (95% CI: 10%, 30%)
had pain deteriorated (score increased by 1 unit or more). Regarding average pain, 55%
(95% CI: 43%, 67%) had pain improved and 28% (95% CI: 17%, 39%) had pain
deteriorated. Assuming the missing data was all failure, our conservative estimation for
the success of improvement was 34% (95% CI: 25%, 43%) and 30% (95% CI: 22%, 38%)
for worst and average pain respectively.
Changes regarding different pain scores on BPI based on available data are tabulated in
Table 5.4. Among the 64 patients who completed the first follow-up questionnaires, the
mean improvement was -1.09 (95% CI: -1.69, -0.50) and -0.86 (95% CI: -1.40, -0.32) in
worst and average pain score respectively. At second follow-up, average reduction in
worst and average pain score among the 15 patients were -2.33 (95% CI: -3.85, -0.81)
and -1.93 (95% CI: -3.31, -0.55) respectively. Sensitivity analyses were tabulated in Table
5.5 (best case imputation), Table 5.6 (worst case imputation) and Table 5.7 (LOCF)
respectively. If we assumed all the missing data were of improved cases, the worst and
average pain score changes were -1.58 (95% CI: -1.96, -1.21) and -1.61 (95% CI: -1.97,
-1.25) respectively. If the missing data were of deteriorated cases, the changes were 0.38
(95% CI: -0.082, 0.83) and 0.27 (95% CI: -0.11, 0.66) respectively. Assuming the scores
were unchanged between baseline and follow-up, we found that mean improvement of
worst and average pain were -0.59 (95% CI: -0.92, -0.26) and -0.47 (95% CI: -0.77, -0.16)
respectively.
5.3.4 Disability and Quality of Life Items on Brief Pain Inventory (BPI)
Table 5.8 presents the results of change in disability and quality of life scores on BPI
using available data. Improvement was observed in all the items at first and second
follow-up. At first follow-up, the greatest mean improvement was enjoyment of life with
mean change of -1.98 (95% CI: -2.80, -1.17), followed by normal work with mean
37
change of -1.89 (95% CI: -2.75, -1.03) and general activity with mean change of -1.80
(95% CI: -2.52, -1.08). The mean changes were -3.47 (95% CI: -4.76, -2.18), -3.40 (95%
CI: -5.16, -1.64) and 2.40 (95% CI: -3.74, -1.06) for general activity, normal work and
enjoyment of life respectively at second follow-up. Results from best case, worst case
and LOCF imputation were tabulated in Table 5.9, Table 5.10 and Table 5.11 respectively.
5.3.5 Oswestry Low-Back Pain Disability Index (ODI)
Among the 119 eligible patients, 12 (10%) did not complete the ODI index because they
did not have back related pain. Therefore, we had ODI data from 107 patients (90%) at
baseline, 53 (45%) at first follow-up and 14 patients (12%) at second follow-up. Table
5.12 shows change in Oswestry Disability Index (ODI) obtained from available data. ODI
showed an improvement of -4.15 (95% CI: -10.07, 1.77) at first follow-up and of -8.25
(95% CI: -13.2, -3.31) at second follow-up. Sensitivity analyses with different
approaches were tabulated in Table 5.13.
5.3.6 Pain Treatment Satisfaction Scale (PTSS)
Results from PTSS are tabulated in Table 5.14. At first follow-up, we had available data
from 56 out of 64 patients who had completed first follow-up. Among the 8 patients who
did not complete PTSS, 3 had worst pain reduced; 3 did not have any change in worst
pain; and 2 had worst pain increased. Of the 56 available data, most of the patients (n=24;
74%) agreed (including strongly and somewhat agree) that they were happy with the
duration of pain relief provided by IMS. Most of them (n=46; 82%) found that they had
better physical health and could perform daily activities more easily (n=37; 66%).
Another 39 subjects (70% of the patients) found their mood had improved after treatment
and 35 (63%) had more often leisure activities. Overall, only 6 patients (11%) disagreed
with the statement that their health improved after IMS treatment. There were 20 patients
(36%) highly satisfied with IMS treatment, 28 patients (50%) satisfied and 2 patients (4%)
were not satisfied. Besides, 27 patients (48%) found that the level of pain relief by IMS
exceeded their expectations whereas 13 patients (24%) thought IMS did not meet their
expectations in terms of pain relief. At second follow-up, similar results were obtained.
Most of patients (73%-94%) agreed with the effect of IMS in improving their pain and
38
health related items, except 1 or 2 patients (7 or 13%). And 13 patients (87%) were
satisfied with IMS treatment.
5.3.7 Predictors for Improvement in Worst and Average Pain Score
Multiple logistic regression was performed using the available data at first follow-up to
identify the predictors for worst pain and average pain improvement (improvement was
defined as reduction of pain score by 1 unit or more on BPI; otherwise it was a failure).
The logistic regression model was mainly exploratory, so p-values were not provided.
Results for worst and average pain improvement are tabulated in Table 5.15 and Table
5.16 respectively. Odds ratio greater than one means the particular level has higher
tendency to have an improvement when compared to the reference level. From the results,
it seemed that initial pain score was associated with pain improvement. The higher the
initial pain score, the greater the probability of pain improvement. Also, there seemed a
practitioner effect. Practitioner D seemed to have higher odds of pain improvement.
His/her patients have higher probability of improving pain when compared to those
treated by other practitioners. Regarding other predictors (age, gender and pain duration),
results were not consistent and thus, these predictors seemed not to be associated with
pain improvement.
5.4 Discussion
In this study, with all the available date, we found that the success rate of IMS in
improving worst and average pain (at least 1 unit reduction in pain score) after four IMS
treatments was 63% (95% CI: 51%, 75%) and 55% (95% CI: 43%, 67%) respectively
among 64 patients. At second follow-up, the improvement was 67% and 73%
respectively among 15 patients. Our conservative analyses of success rate (assuming
missing values were all unsuccessful cases) were 34% (95% CI: 25%, 43%) and 30%
(95% CI: 22%, 38%) respectively for worst and average pain improvement. Considering
the difficulty in treating chronic myofascial pain, this conservative success rate could be
interesting to be considered, should it be confirmed in the long term. Also, among 119
patients with eligibility criteria treated at the clinic, 64 (54%) completed first follow-up
assessment. Of which, 32 left the clinic before the fourth treatment and 14 did not want to
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complete questionnaires. This population may not necessarily represent failure of IMS
because we found positive comments from the practitioner in the chart. Comments,
such as “doing better”, “good progress”, “decrease numbness”, “increased mobility” and
“decreased pain” were found in 39 patient charts (71%) out of 55 missing information. If
we consider these patients who left the clinic before first follow-up assessment were
“success”, the success rates changed from 34% and 30% to 66% and 63% for worst and
average pain respectively.
Our estimation based on available data for mean improvement of worst and average pain
were -1.09 (95% CI: -1.69, -0.50) and -0.86 (95% CI: -1.40, -0.32) respectively at first
follow-up. And they were -2.33 (95% CI: -3.85, -0.81) and -1.93 (95% CI: -3.31, -0.55)
respectively at second follow-up. Results from worst case imputation were not too bad,
mean deterioration of worst and average pain were 0.38 (95% CI: -0.082, 0.83) and 0.27
(95% CI: -0.11, 0.66) respectively.
Compared to other high quality acupuncture studies (Brinkhaus et al 2006, Leibing et al
2002, Molsberger et al 2002), the effect size for average pain improvement in our study is
relatively smaller. The population in these trials are similar to the one treated at the IMS
clinic: Patients with chronic low back pain for more than 6 months, with a mean age
ranging from 48 to 54 and a proportion of female ranging from 42 to 64%. The mean pain
duration was between 9.6 (sd=8.2) and 14.7 (11.0) years while the mean baseline pain
intensity varied from 4.8 (sd=1.8) to 6.6 (sd=1.5) on a 10-cm Visual Analog Scale (VAS).
None of these studies provided changes in worst pain score. These studies either used the
last values carried forward or the intention to treat approach. In the acupuncture group,
the within patient change in average pain score immediately after treatments (number of
treatments were 12 in studies by Brinkhaus and Molsberger; 20 in Leibing’s study) varied
from -2.1 (sd=2) to -3.0 (sd=1.8). For our study, the average change was -0.86 (sd=2.18)
after four treatments and -1.93 (sd=2.49) after eight treatments. The smaller within
patient mean difference observed in our study compared to the one observed in the
acupuncture trials may be due to the difference in effectiveness between IMS and
acupuncture. However, apart from a possibility of existing real difference between the
40
two techniques, we also need to consider the following explanations. Patients treated by
IMS received less treatment sessions than those in acupuncture trials, which may be an
important factor in treatment effect. Our results reflect the mean difference after 4 or 8
IMS treatments, while some patients received 12 or 20 treatments in the acupuncture
studies. Because of the high cost of IMS treatments (CAD$100 for assessment and
CAD$70 for successive treatments), it may happen that patients leave the clinic without
receiving optimal treatments. Besides, our results are generated from usual clinical
practice rather than from an experiment. Patients involved in clinical trials tend to show
higher improvements in response due to the fact that they are being studied: Hawthorne
effect (McCarney et al 2007): the classic difference between “efficacy” and
“effectiveness”. Also, positive bias may occur in these studies as we did not know
whether there were independent investigators in these trials. When we have practitioners
who are likely to bias in favour of needling technique to carry out their own trials,
positive bias may happen because practitioners’ expectations towards trial outcomes may
influence patients’ responses in single blinding trials.
Compare to drug trials of chronic low back pain patients, the mean difference we found
using available data was comparable. Two studies compared the effect between
administration of combination tablets of tramadol and acetaminophen and placebo tablets,
the standardized mean difference (SMD, mean difference divided by standard deviation)
was -1.01 (95% CI: -1.24, -0.79) and -0.54 (95% CI: -0.76, -0.31) respectively (Peloso et
al 2004, Ruoff et al 2003). A Cochrane review of antidepressants against placebo (9 trials)
found SMD of 0.41 (95% CI: 0.22-0.61) which favours effect of antidepressant while in
our study, if we consider SMD from available data (1st follow-up: 0.39 [0.86/2.18], 2nd
follow-up: 0.78 [1.93/2.49]), our results were comparable to drug trials.
Our study also found that IMS had the effect of improvement on disability and quality of
life outcomes at both first and second follow-up. Consistent finding was also obtained
from Oswestry Disability Index (ODI) although the result was less important in
magnitude. Regarding IMS treatment satisfaction, nearly 90% of patients were satisfied
with the treatment. More than 60% were happy with the duration of pain relief and were
41
able to perform daily activities more easily. This positive result, however, are difficult to
interpret given the short term follow-up at the clinic.
Our logistic model showed that initial pain score seemed to be associated with pain
improvement. The higher the pain score before treatment, the higher the tendency to
report improvement after treatment. This result may be due to a “regression to mean”
effect. Logistic regression also shows some important difference between practitioners.
Such a “practitioner effect” cannot receive satisfactory explanation within the context of
an observational study; however it raises the question of a possible difference in
treatment administration among practitioners at the clinic. If real, the problem has to be
resolved before conducting the randomized trial with more training and standardization
of practice to ensure high consistency before implementing the study.
Overall, this study showed positive results regarding IMS in relieving chronic pain and
improving pain consequences in the short term. However, it has several important
limitations. This study only shows the immediate treatment effect after four and eight
IMS treatments without long-term follow-up. Also, some patients may leave the clinic
even they still have pain because of the cost of treatment. It is then possible that some
patients did not get the optimal number of treatment sessions to relieve their pain at the
time of analysis. However, our results may reflect IMS effectiveness in controlling pain
in reality. Besides, our results were generated from usual clinical practice without control
group and are prone to selection bias due to the important attrition. Our primary analysis
was based on available data and assumed the missing information was independent to
either observed or unobserved outcomes. In practice, it is not always the case. Our
missing information may be due to treatment effect. Patients may leave clinic before
follow-up assessment because they are free of pain or they feel worse after treatment.
Therefore, we did not draw any conclusion regarding IMS effect from this study, instead
we performed several sensitivity analyses to present results in different scenarios of
missing data including best, worst and unchanged case scenario.
42
5.5 Conclusion
This study showed positive results regarding the short term effect of IMS in improving
chronic myofacial pain and the pain related consequences. The mean pain, disability and
quality of life scores also showed improvement at follow-up. Although this study suffered
from attrition bias, the effect of IMS is still worth to be considered given the fact that
nearly half of the patients included in this study had pain suffered from more than 3 years
and the success rate of pain improvement was at least 30%. Considering the difficulty in
treating chronic pain, we suggested conducting a high quality RCT to further evaluate the
effect of IMS. Furthermore, as there seems a practitioner effect in determining the
success of pain improvement, we decided to conduct an inter-rater reliability test to
examine the consistency among practitioners in treating patients. Good consistency has to
be achieved before the conduct of RCT.
43
Tables Table 5.1: Demographic Characteristics of Patients Not Included in the Analysis
Patients who did not complete baseline questionnaires
n=21
Patients who completed baseline questionnaires
n=119 Mean Age 48.3 (sd=12.2) 46.6 (sd=12.9) Gender (F) 14 (67%) 70 (59%)
Pain Duration less than 1 year 5 (24%) 20 (17%)
1 to 3 years 5 (24%) 42 (35%) 4 to 6 years 4 (19%) 19 (16%) 7 to 10 years 3 (14%) 11 (9%)
more than 10 years 4 (19%) 27 (23%) Region of Pain
Head 1 (5%) 18 (15%) Neck and shoulder 13 (62%) 43 (36%)
Upper limbs 3 (14%) 25 (21%) Upper back 6 (28%) 36 (30%) Lower back 9 (43%) 72 (61%) Lower limbs 7 (33%) 49 (41%)
44
Table 5.2: Demographic Characteristics
All included patients n=119 (100%)
Completed 1st follow-upn=64 (54%)
Completed 2nd follow-up n=15 (13%)
Mean Age 46.6 (sd=12.9) 46.2 (sd=12.5) 42.5 (sd=11.0) Gender (F) 70 (59%) 38 (59%) 9 (60%)
Pain Duration less than 1 year 20 (17%) 13 (20%) 2 (13%)
1 to 3 years 42 (35%) 25 (39%) 7 (47%) 4 to 6 years 19 (16%) 8 (12.5%) 2 (13%) 7 to 10 years 11 (9%) 8 (12.5%) 3 (20%)
more than 10 years 27 (23%) 10 (16%) 1 (7%) Region of Pain
Head 18 (15%) 8 (12.5%) 3 (20%) Neck and shoulder 43 (36%) 26 (40%) 7 (47%)
Upper limbs 25 (21%) 12 (18%) 3 (20%) Upper back 36 (30%) 18 (28%) 7 (47%) Lower back 72 (61%) 30 (47%) 11 (73%) Lower limbs 49 (41%) 28 (44%) 8 (53%) Mean Score
Mean worst pain at baseline
6.93 (sd=2.02) 6.92 (sd=2.23) 6.73 (sd=2.12)
Mean average pain at baseline
5.15 (sd=1.93) 5.08 (sd=2.06) 4.80 (sd=2.08)
Mean ODI at baseline (%)
30.42 (sd=18.90) 31.22 (sd=19.31) 28.11 (sd=14.24)
45
Table 5.3: Distribution of Pain Intensity Change at Follow-up Using Available Data First Follow-up (n=64, 54%)
Deterioration No change Improvement Worst Pain 13 (20%, 10-30%) 11 (17%, 8-26%) 40 (63%, 51-75%)
Average Pain 18 (28%, 17-39%) 11 (17%, 8-26%) 35 (55%, 43-67%) Second Follow-up (n=15, 13%)
Deterioration No change Improvement Worst Pain 3 (20%) 2 (13%) 10 (67%)
Average Pain 1 (7%) 3 (20%) 11 (73%) Number and percentage with 95% confidence interval (CI); CI is not presented in results of second follow-up because of the small sample size. Deterioration = pain score increased by 1 unit or more No change = pain score were the same at baseline and follow-up Improvement = pain score decreased by 1 unit or more Table 5.4: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Available Data
First Follow-up (n=64, 54%) Mean Difference (sd) 95% Confidence
Intervals p-value
1. Worst pain -1.09 (2.34) -1.69, -0.50 0.0005 2. Least pain -0.63 (2.52) -1.25, 0.0036 0.0513 3. Average pain -0.86 (2.18) -1.40, -0.32 0.0025 4. Pain right now -0.47 (2.86) -1.18, 0.25 0.1948
Second Follow-up (n=15, 13%) Mean Difference (sd) 95% Confidence
Intervals p-value
1. Worst pain -2.33 (2.74) -3.85, -0.81 0.0053 2. Least pain -1.47 (2.10) -2.63, -0.30 0.0171 3. Average pain -1.93 (2.49) -3.31, -0.55 0.0095 4. Pain right now -1.67 (2.58) -3.10, -0.24 0.026
46
Table 5.5: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Best Case Imputation
First Follow-up (n=119) Mean Difference (sd) 95% Confidence
Intervals p-value
1. Worst pain -1.58 (2.09) -1.96, -1.21 <.0001 2. Least pain -1.29 (2.43) -1.70, -0.82 <.0001 3. Average pain -1.61 (1.98) -1.97, -1.25 <.0001 4. Pain right now -1.69 (2.80) -2.20, -1.19 <.0001
Table 5.6: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Worst Case Imputation
First Follow-up (n=119) Mean Difference (sd) 95% Confidence
Intervals p-value
1. Worst pain 0.38 (2.52) -0.082, 0.83 0.1067 2. Least pain 0.62 (2.41) 0.18, 1.06 0.0061 3. Average pain 0.27 (2.11) -0.11, 0.66 0.1584 4. Pain right now 0.62 (2.47) 0.17, 1.07 0.0073
Table 5.7: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using LOCF
First Follow-up (n=119) Mean Difference (sd) 95% Confidence
Intervals p-value
1. Worst pain -0.59 (1.83) -0.92, -0.26 0.0006 2. Least pain -0.34 (1.87) -0.68, 0.0025 0.052 3. Average pain -0.47 (1.66) -0.77, -0.16 0.0028 4. Pain right now -0.25 (2.10) -0.63, 0.13 0.19
47
Table 5.8: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Available Data
First Follow-up (n=64, 54%) Mean
Difference (sd)95% Confidence
Intervals p-value
5a. Interfered general activity -1.80 (2.87) -2.52, -1.08 <.0001 5b. Interfered mood -1.42 (3.36) -2.26, -0.58 0.0012 5c. Interfered walking -1.22 (3.24) -2.04, -0.41 0.004 5d. Interfered normal work -1.89 (3.44) -2.75, -1.03 <.0001 5e. Interfered relations with others -1.38 (3.19) -2.17, -0.58 0.001 5f. Interfered sleep -1.55 (3.57) -2.44, -0.66 0.0009 5g. Interfered enjoyment of life -1.98 (3.28) -2.80, -1.17 <.0001
Second Follow-up (n=15, 13%) Mean
Difference (sd)95% Confidence
Intervals p-value
5a. Interfered general activity -3.47 (2.33) -4.76, -2.18 <.0001 5b. Interfered mood -2.60 (2.50) -3.99, -1.22 0.0013 5c. Interfered walking -3.27 (3.79) -5.37, -1.17 0.0049 5d. Interfered normal work -3.40 (3.18) -5.16, -1.64 0.001 5e. Interfered relations with others -1.60 (2.75) -3.12, -0.079 0.041 5f. Interfered sleep -2.07 (3.61) -4.07, -0.065 0.044 5g. Interfered enjoyment of life -2.40 (2.41) -3.74, -1.06 0.0018
48
Table 5.9: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Best Case Imputation
First Follow-up (n=119) Mean
Difference (sd)95% Confidence
Intervals p-value
5a. Interfered general activity -2.41 (2.52) -2.87, -1.96 <.0001 5b. Interfered mood -2.30 (3.09) -2.86, -1.74 <.0001 5c. Interfered walking -2.24 (3.04) -2.79, -1.68 <.0001 5d. Interfered normal work -2.78 (3.07) -3.34, -2.22 <.0001 5e. Interfered relations with others -2.04 (2.86) -2.56, -1.52 <.0001 5f. Interfered sleep -2.68 (3.38) -3.29, -2.06 <.0001 5g. Interfered enjoyment of life -2.38 (3.10) -2.94, -1.82 <.0001
Table 5.10: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Worst Case Imputation
First Follow-up (n=119) Mean
Difference (sd)95% Confidence
Intervals p-value
5a. Interfered general activity 0.35 (3.30) -0.25, 0.95 0.2496 5b. Interfered mood 0.53 (3.57) -0.11, 1.18 0.1055 5c. Interfered walking 0.39 (3.09) -0.17, 0.96 0.1717 5d. Interfered normal work -0.04 (3.44) -0.67, 0.58 0.8907 5e. Interfered relations with others 0.22 (3.07) -0.34, 0.78 0.4376 5f. Interfered sleep 0.75 (4.14) -0.002, 1.50 0.0507 5g. Interfered enjoyment of life 1.19 (4.51) 0.38, 2.00 0.0049
Table 5.11: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using LOCF
First Follow-up (n=119) Mean
Difference (sd)95% Confidence
Intervals p-value
5a. Interfered general activity -0.97 (2.28) -1.38, -0.55 <.0001 5b. Interfered mood -0.77 (2.55) -1.23, -0.30 0.0014 5c. Interfered walking -0.64 (2.44) -1.09, -0.20 0.0049 5d. Interfered normal work -1.02 (2.68) -1.50, -0.53 <.0001 5e. Interfered relations with others -0.74 (2.43) -1.18, -0.30 0.0012 5f. Interfered sleep -0.83 (2.72) -1.33, -0.34 0.0011 5g. Interfered enjoyment of life -1.08 (2.59) -1.54, -0.60 <.0001
49
Table 5.12: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Available Data First Follow-up (n=53, 45%) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) -4.15 (21.48) -10.07, 1.77 0.17 Second Follow-up (n=14, 12%) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) -8.25 (8.56) -13.2, -3.31 0.0032
Table 5.13: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Sensitivity Analyses Best case imputation at first follow-up (n=107) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) -8.72 (18.59) -12.27, -5.18 <.0001 Worst case imputation at first follow-up (n=107) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) 5.66 (22.21) 1.43, 9.90 0.0093 LOCF at first follow-up (n=107) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) -2.69 (15.66) -5.69, 0.32 0.071
50
Table 5.14: Results from Pain Treatment Satisfaction Scale (PTSS)
First follow-up with available data (n=56, 47%) Strongly
agree n (%)
Somewhat agree n (%)
Neither agree nor disagree
n (%)
Somewhat disagree
n (%)
Strongly disagree
n (%)
1. happy with duration of pain relief
12 (34%) 22 (40%) 11 (20%) 3 (5%) 1 (2%)
2. pain relief quickly enough 11 (20%) 20 (36%) 19 (34%) 5 (9%) 1 (2%) 3. better physical health 23 (41%) 23 (41%) 7 (13%) 1 (2%) 2 (4%) 4. better outlook 23 (41%) 17 (30%) 12 (21%) 2 (4%) 2 (4%) 5. perform daily activities more easily
17 (30%) 20 (36%) 15 (27%) 3 (5%) 1 (2%)
6. more often leisure activities
16 (29%) 19 (34%) 19 (34%) 1 (2%) 1 (2%)
7. do things more independently
15 (27%) 19 (34%) 19 (34%) 2 (4%) 1 (2%)
8. better relationship with others
15 (27%) 15 (27%) 22 (39%) 3 (5%) 1 (2%)
9. improve mood 20 (36%) 19 (34%) 14 (25%) 3 (5%) 0 (0%) 10. concentrate better 16 (29%) 14 (25%) 20 (36%) 5 (9%) 1 (2%) 11. move around more easily 21 (38%) 18 (32%) 14 (25%) 3 (5%) 0 (0%) Very
satisfied Satisfied Neither
satisfied nor dissatisfied
Dissatisfied Very dissatisfied
12. overall satisfaction with IMS
20 (36%) 28 (50%) 6 (11%) 2 (4%) 0 (0%)
Greatly exceeds
expectation
Somewhat exceeds
expectation
Meet expectation
Not quite meet
expectation
Not meet expectation
at all 13. level of pain relief 9 (16%) 18 (32%) 16 (29%) 11 (20%) 2 (4%) Definitely Probably Don’t know Probably
not Definitely
Not 14. IMS could be more effective
5 (9%) 21 (38%) 24 (43%) 6 (11%) 0 (0%)
51
Table 5.14: Results from Pain Treatment Satisfaction Scale (PTSS) (Continued)
Second follow-up with available data (n=15, 13%) Strongly
agree n (%)
Somewhat agree n (%)
Neither agree nor disagree
n (%)
Somewhat disagree
n (%)
Strongly disagree
n (%)
1. happy with duration of pain relief
7 (47%) 7 (47%) 0 (0%) 1 (7%) 0 (0%)
2. pain relief quickly enough 4 (27%) 9 (60%) 1 (7%) 1 (7%) 0 (0%) 3. better physical health 9 (60%) 5 (33%) 1 (7%) 0 (0%) 0 (0%) 4. better outlook 6 (40%) 9 (60%) 0 (0%) 0 (0%) 0 (0%) 5. perform daily activities more easily
9 (60%) 4 (27%) 1 (7%) 1 (7%) 0 (0%)
6. more often leisure activities
8 (53%) 3 (20%) 3 (20%) 1 (7%) 0 (0%)
7. do things more independently
9 (60%) 3 (20%) 2 (13%) 1 (7%) 0 (0%)
8. better relationship with others
6 (40%) 5 (33%) 3 (20%) 1 (7%) 0 (0%)
9. improve mood 7 (47%) 7 (47%) 1 (7%) 0 (0%) 0 (0%) 10. concentrate better 5 (33%) 6 (40%) 2 (13%) 2 (13%) 0 (0%) 11. move around more easily 8 (53%) 5 (33%) 1 (7%) 1 (7%) 0 (0%) Very
satisfied Satisfied Neither
satisfied nor dissatisfied
Dissatisfied Very dissatisfied
12. overall satisfaction with IMS
10 (67%) 3 (20%) 2 (13%) 0 (0%) 0 (0%)
Greatly exceeds
expectation
Somewhat exceeds
expectation
Meet expectation
Not quite meet
expectation
Not meet expectation
at all 13. level of pain relief 7 (47%) 3 (20%) 3 (20%) 2 (13%) 0 (0%) Definitely Probably Don’t know Probably
not Definitely
Not 14. IMS could be more effective
3 (20%) 6 (40%) 4 (27%) 0 (0%) 2 (13%)
52
Table 5.15: Results from Multiple Logistic Regression with Response = Worst Pain Improvement
multiple logistic regression with response = worst pain improvement Reference Odds ratio 95% confidence interval
Age <31 Age >60 14.12 0.54, 371.53 Age 31-40 Age >60 1.13 0.098, 13.18 Age 41-50 Age >60 0.69 0.068, 6.99 Age 51-60 Age >60 3.23 0.35, 30.21
Practitioner A Practitioner D 0.28 0.025, 3.14 Practitioner B Practitioner D 0.26 0.015, 4.38 Practitioner C Practitioner D 0.27 0.019, 3.76
Gender F Gender M 0.64 0.13, 3.08 Pain duration <1 yr Pain duration>10 yrs 0.32 0.032, 3.21
Pain duration 1-3 yrs Pain duration>10 yrs 1.04 0.14, 7.71 Pain duration 4-6 yrs Pain duration>10 yrs 3.13 0.16, 60.62 Pain duration 7-10 yrs Pain duration>10 yrs 1.15 0.10, 13.0 Initial worst pain 1-3 Initial worst pain 7-10 0.13 0.01, 1.63 Initial worst pain 4-6 Initial worst pain 7-10 0.41 0.06, 2.82
Table 5.16: Results from Multiple Logistic Regression with Response = Average Pain Improvement
multiple logistic regression with response = average pain improvement Reference Odds ratio 95% confidence interval
Age <31 Age >60 0.82 0.044, 15.26 Age 31-40 Age >60 0.34 0.02, 5.88 Age 41-50 Age >60 0.068 0.004, 1.05 Age 51-60 Age >60 0.21 0.014, 3.07
Practitioner A Practitioner D 0.021 <0.001, 0.049 Practitioner B Practitioner D 0.028 <0.001, 0.84 Practitioner C Practitioner D 0.12 0.006, 2.41
Gender F Gender M 1.0 0.19, 5.40 Pain duration <1 yr Pain duration>10 yrs 0.36 0.029, 4.51
Pain duration 1-3 yrs Pain duration>10 yrs 1.05 0.096, 11.54 Pain duration 4-6 yrs Pain duration>10 yrs 9.59 0.45, 206.30 Pain duration 7-10 yrs Pain duration>10 yrs 0.64 0.034, 11.97 Initial worst pain 1-3 Initial worst pain 7-10 0.007 <0.001, 0.153 Initial worst pain 4-6 Initial worst pain 7-10 0.043 0.004, 0.42
53
Figures Figure 5.1: Flow Chart for Population Identification
Refuse to Complete
Questionnaires n=21
Acute Pain (pain for less than
3 months) n=15
No 1st Follow-up Questionnaires
n=55
Completed 2nd Follow-up Questionnaires
n=15
Received IMS treatment (April 1st, 09 – Feb 1st, 10)
n=155
Chronic Pain (pain persists for 3 months or more)
n=140
Completed Baseline Questionnaires
n=119
Completed 1st Follow-up Questionnaires
n=64
No 2nd Follow-up Questionnaires
n=49
Left Clinic n= 32
Refuse to completen= 14
Censoring n= 9
Left Clinic n= 17
Refuse to completen= 22
Censoring n= 10
54
CHAPTER 6: Study 3-Assessing the Inter-Rater Reliability of Intramuscular
Stimulation Practitioners
6.1 Introduction
The second chart review (chapter 5) showed the possibility of a practitioner effect with
regard to pain improvement: three practitioners had only ¼ probability of the fourth one
to reach success (at least 1 unit reduction in worth pain score). Differential effect is a
real possibility in all needling techniques as there is a learning curve. Moreover, we
already described in chapter 2 the difficulty to make a precise and reliable diagnosis of
myofascial pain which leads to treatment strategy, hence effects. Therefore, we felt that
testing the consistency of making myofascial pain diagnosis and treating patients among
IMS practitioners was an important information to collect before carrying out a RCT.
We decided then to carry out an inter-rater reliability study to assess the consistency
among five IMS practitioners in identifying the same signs of myofascial pain. The
primary objective of the study was to test the agreement among IMS practitioners in
identifying number of tender taut bands along the spine and in the body regions.
Secondary objective was to test the consistency of IMS practitioners in recording the taut
bands within precise muscles and the signs of autonomic dysfunction.
6.2 Methods
6.2.1 Study Design
The inter-rater reliability study was conducted during one day in one IMS clinic in
Vancouver. Twenty patients who suffered from chronic myofascial pain were invited to
participate in the test. Each patient was examined by five different IMS practitioners at
the clinic. Practitioners carried out 15 minutes clinical examination on every patient and
recorded clinical findings such as tender taut bands and signs of autonomic dysfunction
on standard forms. Results were collected and analyzed by research team members who
were independent to the clinic.
6.2.2 Study Sample
Recruitment was done at IMS clinic during office hours two weeks before the study
55
started. Practitioners invited their current patients who suffered from myofascial pain in
lower back or lower extremities for at least 3 months to participate in the study. There
was no age or sex restriction. A total of 20 patients were then recruited and each of them
signed a consent form.
6.2.3 Practitioners
All five certified IMS practitioners practicing at the IMS clinic participated in this study.
All practitioners had practiced IMS for over 5 years and three of them were current IMS
instructors. All of them had received standard IMS training to become IMS certified,
following Gunn’s book (2007) which describes standard clinical examination and
treatment strategy as a reference.
Before the inter-rater reliability study, a meeting of 2 hours with IMS practitioners and
research team members was held to discuss the study protocol and review definitions of
clinical signs and treatment strategy to ensure common interpretation by practitioners.
6.2.4 Study Procedures
This was a one day test with four different sessions of 5 subjects each. The five subjects
were allocated to five different rooms where clinical examination took place. Therefore,
the five IMS practitioners could examine the five subjects at the same time. Each
examination took about 15 minutes. When practitioners finished one examination, they
handed in the completed examination form to the research coordinator and automatically
shifted to the next room to examine another patient. The process continued, until every
practitioner had examined the five subjects. Another session took place right after five
minutes break.
6.2.5 Clinical Examination
IMS deep needling technique targets specifically points of palpable muscle contraction
(tender taut band) and the associated paraspinal muscles (semispinalis, rotators,
multifidus and spinalis) along the spine. Therefore, identification of palpable tender taut
bands and the associated tender spinous muscles are the keys for clinical examination and
56
the subsequent strategic treatment plan. In this study, tender taut band defined as a
palpable rope-like hardening of muscles defined as a group of muscle fibers that may be
passively stretched by the contracture of contraction knots in a trigger point in the center
of the fibers (Simon 1992).
In this reliability test, examination was confined to the lower part of the body.
Practitioners focused palpation on spinous muscles along T6-T12 and L1-L5. Muscles on
the back (Latissimus dorsi, quadratus lumborum, lliocostalis, longissimus), around hip
and thigh (tensor fasciae latae, gluteus medius and maximus, pectineus, adductor longus
and magnus, rectus femoris, quadratus medialis and lateralis, pes anserinus, semi
tendinosis and membranosis, biceps femoris) and leg (gastrocnemius, soleus, tibialis
anterior, extensor digitorum longus, peroneus) were examined.
Autonomic dysfunction is very common in myofascial pain patients. Identifying
autonomic symptoms can help finding contracted muscles which are difficult to be
palpated. In this study, autonomic disorders such as differential sweating (sudomotor
reflex), skin temperature (vasomotor reflex), goose bumps (pilomotor reflex), trophic
changes (hair loss or cracking nails) and oedema were documented during clinical
examination to test the consistency of findings.
.
6.2.6 Outcome Measures
Primary outcome was the identification of number of tender taut band in body regions
(back, hip and thigh, leg) and along the spine (thoracic and lumbar segments).
Secondary outcomes were the identification of tender taut band at each muscle level and
the identification of signs of autonomic dysfunction including oedema, pilomotor reflex
(goose bumps), decrease in skin temperature (vasomotor reflex), abnormal sweating
(sudomotor reflex) and trophic changes (cracking nails or hair loss). Outcomes
assessment was collected on a standardized form that had the list of all muscles to
examine and signs of autonomic dysfunction. A check box was next to each item on the
form. Practitioners checked the corresponding boxes when they identified the presence of
57
tender taut band in the particular region, muscles and/or presence of autonomic
dysfunction.
6.2.7 Ethics
The study proposal and related materials were approved by UBC Clinical Research
Ethics Board on 8th June, 2009.
6.2.8 Statistical Analysis
Primary analysis focused on assessing the consistency among practitioners in identifying
number of taut bands in spinous muscles, back muscles, hip and thigh muscles, and leg
muscles using intra-class correlation coefficient (ICC). Intra-class correlation coefficient
(ICC) is commonly used in measuring inter-rater reliability when continuous variables
(i.e. counting the number of taut bands in this study) are applied where ICC=0 indicates
no agreement and ICC=1 indicates perfect agreement (Shrout & Fleiss 1979).
Interpretation of ICC is similar to kappa statistics which is shown below (Garson 2009).
Secondary analysis was the agreement among practitioners in identifying each item on
autonomic dysfunctions and identifying taut band in each muscle (presence/absence)
using multiple raters Kappa. Multiple raters Kappa is widely used in measuring reliability
for nominal variables and discounting for the proportion of agreement expected by
chance alone if more than 2 raters are involved (Fleiss 1971). Kappa statistic in general
can be interpreted as follow: 0=poor, 0.01–0.20=slight, 0.21–0.40=fair,
0.41–0.60=moderate, 0.61–0.80=substantial and 0.81–1=almost perfect agreement (Sim
et al 2005). We also computed overall kappa values for each extremity region and for
autonomic dysfunction by simple averaging.
All statistics were calculated at alpha=0.05 and were performed with SAS version 9.1
Windows, SAS Institute Inc., NC, USA.
58
6.3 Results
6.3.1 Sample Characteristics
Twenty subjects were recruited in the study of which 12 (60%) were female. Mean age of
these 20 participants was 48.8 (sd =11.2). Their regions of pain were: low back pain for 9
(45%), leg pain for 4 (20%) and 7 (35%) had both back and leg pain. All participants
were diagnosed as chronic myofascial pain patients and their pain persisted at least 3
months by the time they received first IMS treatment. Most of them (55%) had suffered
from pain for 1-3 years at the time of the test. 6 of them (30%) had pain for 4-6 years and
3 (15%) had pain for less than 1 year but more than 3 months.
6.3.2 Inter-rater Reliability of Identifying Tender Taut Bands
6.3.2.1 Identification of Number of Taut Bands in Different Body Regions
Consistency of identifying number of taut bands in different parts of the body was
tabulated in Table 6.1. The ICC values for thoracic and lumber spinous muscles were
0.66 and 0.68 respectively. ICC value was 0.64 for the number of taut bands found in
muscles at the back. For hip/thigh region, the consistency in identifying the number of
taut bands was 0.77. Finally the ICC value was 0.69 for leg muscles. All the ICC values
obtained indicated substantial agreement among practitioners in identifying number of
taut bands in each region.
6.3.2.2 Identification of Taut Bands in Each Muscle
Agreement in identifying taut bands in each muscle in back region, hip and thigh region
and leg region were tabulated in Table 6.2, Table 6.3 and Table 6.4 respectively. Table 6.2
shows reliability in back muscles. Kappa values in back muscles ranged from 0.13 to
0.39. The average kappa value was 0.25 (sd=0.09) showing fair agreement. Table 6.3
shows the multiple raters kappa values of tender taut bands in thigh or hip muscles. The
kappa values ranged from -0.05 (poor agreement) to 0.46 (moderate agreement). The
average was 0.18 (sd=0.1) showing overall slight agreement. For leg muscles, multiple
raters kappa values were from 0.03 to 0.34 indicating slight or fair agreement (Table 6.4).
The average kappa was 0.16 (sd=0.1).
59
6.3.2.3 Identification of Autonomic Dysfunction
Multiple-raters kappa results for autonomic dysfunction identification reliability are
presented in Table 6.5. It shows that the reliability of identifying autonomic dysfunction
was between -0.11 and 0.2 (mean=0.016, sd=0.13) which fell in the categories of poor
agreement or slight agreement.
6.4 Discussion
In identifying the number of tender taut bands in different regions, there was a good
consistency among practitioners shown by ICC values which varied from 0.64 to 0.77
(Table 6.1). However, relatively low kappa values were obtained when measuring the
consistency in identifying taut bands in specific muscles. Kappa values ranged from -0.05
(poor agreement) to 0.46 (moderate agreement) were obtained (Tables 6.2 to 6.4). These
results indicated substantial agreement among practitioners in identifying number of taut
bands to treat in different parts of body, but practitioners might treat different muscles in
that particular region due to great discrepancy (low kappa) at muscle level. This maybe
due to the fact that IMS practitioners have difficulty in identifying muscle anatomy
correctly or the fact that IMS practitioners are examining patients in different ways.
However, it raises the question of consistency in dispensing the IMS intervention
between different IMS practitioners. This result may then explain the difference in effect
between practitioners observed during the second chart review (chapter 5).
For the reliability in examining autonomic dysfunction, the kappa statistics indicated that
practitioners reached only poor or slight agreement with highest kappa value achieved for
skin oedema (kappa=0.2). Poor agreement was found in identifying vasomotor, pilomotor,
sudomotor dysfunction and trophic changes.
Reason for the poor consistency may receive several explanations. Firstly, it was
acknowledged that practitioners relied more on their own experience and usual practice to
examine patients rather than following strictly the original standard of examination.
Secondly, practitioners claimed that it was exhausting to examine 20 patients with too
many variables (21 pairs of muscles, 12 spinal segments, 5 autonomic symptoms) to
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record. They believed that time was too limited to carry out a thorough clinical
examination. Finally, autonomic symptoms such as vasomotor and sudomotor reflex were
considered to be too subjective to record.
Although this study suggests inconsistency among IMS practitioners in identifying
specific muscle taut band, the results were useful in giving an interesting insight for
improving consistency among the team of 5 IMS practitioners. The results obtained in
this study may then represent a baseline reference against which we can compare the
team performance after proper training. From the experience in this study, we
recommended IMS practitioners’ team to carry out comprehensive training and
demonstration to ensure standardization of the examination and consistency in reporting
signs. We also recommended practitioners to discuss and share their examination
experience with each other to reach a higher degree of agreement. Good collaboration
between practitioners will be the bridge to success. To avoid that practitioners’ fatigue
interfere with the quality of examination, we suggested that examination should focus
only on a limited number of key muscles, to be decided and agreed upon in advance – or
alternatively to give more time to examine the patients. If we keep the same format
(about 15 minutes per patient), we recommended to drop by two-third the number of
examination variables. Less important muscles should be eliminated. Also, the
examination form should be developed by all practitioners so that all the examination
variables on the form are agreed by all practitioners and practitioners feel comfortable
using the form. Finally, subjective outcomes such as vasomotor and sudomotor reflex
should be eliminated.
6.5 Conclusion
From this study, good agreement between IMS practitioners was found at regional level
regarding the number of taut bands identified. However, low consistency was found in
examining taut bands in each muscle and identifying autonomic dysfunctions. This result
raises the question of possible IMS treatment discrepancy between practitioners.
Substantial agreement among practitioners in examining patients has to be achieved
before carrying out a RCT.
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Tables Table 6.1: Intra-class Correlation Coefficient (ICC) for Identifying the Number of Taut Bands in Different Regions Regions Intra-class Correlation Coefficient (ICC)Spinous muscles from T6 to T12 0.66 Spinous muscles from L1 to L5 0.68 Muscles at the back 0.64 Muscles at hip and thigh area 0.77 Muscles at leg area 0.69 Table 6.2: Multiple Raters Kappa of Identifying Taut Band in Each Back Muscle L/R Muscles Kappa 95% CI (lower) 95% CI (upper) L Latissimus dorsi 0.14 0.00 0.28 R Latissimus dorsi 0.22 0.08 0.36 L quadratus lumborum 0.26 0.13 0.40 R quadratus lumborum 0.34 0.20 0.48 L lliocostalis 0.20 0.06 0.34 R lliocostalis 0.30 0.16 0.44 L longissimus 0.13 -0.01 0.27 R longissimus 0.39 0.25 0.53 Average 0.25 SD=0.09
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Table 6.3: Multiple Raters Kappa of Identifying Taut Band in Each Hip/Thigh Muscle Kappa 95% CI (lower) 95% CI (upper) L tensor fasciae latae 0.32 0.18 0.46 R tensor fasciae latae 0.16 0.02 0.30 L gluteus medius 0.17 0.03 0.31 R gluteus medius 0.07 -0.07 0.21 L gluteus maximus 0.28 0.14 0.42 R gluteus maximus 0.16 0.02 0.30 L pectineus 0.14 0.00 0.28 R pectineus 0.09 -0.05 0.23 L adductor longus and magnus 0.13 -0.01 0.26 R adductor longus and magnus 0.15 0.02 0.29 L rectus femoris 0.19 0.06 0.33 R rectus femoris 0.46 0.32 0.60 L quadratus medialis -0.05 -0.19 0.08 R quadratus medialis 0.12 -0.02 0.26 L quadratus lateralis 0.15 0.02 0.29 R quadratus lateralis 0.25 0.11 0.38 L pes anserinus 0.14 0.00 0.28 R pes anserinus 0.22 0.08 0.36 L semi tendinosis & membranosis 0.26 0.12 0.40 R semi tendinosis & membranosis 0.21 0.08 0.35 L biceps femoris 0.16 0.02 0.30 R biceps femoris 0.12 -0.02 0.26 Average 0.18 SD=0.10
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Table 6.4: Multiple Raters Kappa of Identifying Taut Band in Leg Muscle Kappa 95% CI (lower) 95% CI (upper) L gastrocnemius lateral head 0.14 0.00 0.28 R gastrocnemius lateral head 0.04 -0.10 0.18 L gastrocnemius medial head 0.34 0.20 0.48 R gastrocnemius medial head 0.09 -0.05 0.23 L soleus 0.16 0.02 0.30 R soleus 0.04 -0.10 0.18 L tibialis anterior 0.16 0.02 0.30 R tibialis anterior 0.14 0.00 0.28 L extensor digitorum longus 0.21 0.07 0.35 R extensor digitorum longus 0.03 -0.10 0.17 L peroneus 0.24 0.10 0.38 R peroneus 0.30 0.16 0.44 Average 0.16 SD=0.10 Table 6.5: Multiple Raters Kappa of Identifying Autonomic Dysfunction Kappa 95% CI (lower) 95% CI (upper) Vasomotor (decrease in skin temperature)
0.03 -0.11 0.16
Pilomotor (goosebumps) -0.12 -0.25 0.02 Sudomotor (abnormal sweating) -0.11 -0.25 0.03 Trophic changes (cracking nails/ hair loss)
0.03 -0.07 0.13
Oedema 0.20 0.07 0.34 Average 0.016 SD= 0.13
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CHAPTER 7: Summary of Findings, Conclusion and Future Work
7.1 Introduction
Chronic myofascial pain is a public health problem without efficacious treatment.
Common drugs such as antidepressants and opioids are of limited long term efficacy and
often associated with numerous adverse events. Complementary and alternative medicine
(CAM) is therefore popular for people who suffer from chronic pain. One common CAM
is dry needling which includes traditional Chinese acupuncture and dry needling of
trigger point (TrP). Intramuscular stimulation (IMS) is a popular form of TrP needling
and is utilized in multidisciplinary pain centers. Many chronic pain patients seem to
appreciate the effects of IMS in alleviating their pain as seen by letters and testimonials.
However, there is no solid clinical evidence supporting IMS effect. We feel that it is
important to further evaluate the effect of IMS by a high quality randomized controlled
trial (RCT). This thesis included three studies which were conducted to help design and
exploring the feasibility of conducting an IMS RCT in terms of recruitment, population
characteristics and sample size estimation. The main findings of the three studies are
summarized as follow.
7.2 Summary of Findings
Study 1: First Retrospective Chart Review
This study describes well the population treated at the IMS clinic. Of the 100 studied
patients, 30% had pain for 10 or more years and most of the patients (more than 80%)
had more than one region of pain. Lower back pain was the leading pain complaint,
followed by neck and shoulder pain. The median for the number of treatments received
was six. Of the 100 charts, 78 had records of pain control by practitioners. Of which 74
were qualified as improvements. Assuming the missing information in 22 charts
corresponded to pain worsening, the success rate of IMS in improving pain would be
74% which met our study hypothesis (at least 50%). However, these results were prone to
a positive bias because of practitioners’ subjective report regarding pain improvement.
We then tried to contact patients by phone with the objective to collect patients’
comments regarding treatment effect. Because of the low response rate (12%) in this
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telephone interview, the results cannot be interpreted. These results lead the clinic to
modify the patient chart recordings by incorporating standard questionnaires for patients
to fill out. So we decided to carry out a second chart review 10 months after
implementing the new patient chart with standard recordings from patients’ feedback.
Study 2: Second Retrospective Chart Review
The population characteristics obtained from this chart review were similar to the first
chart review. Of the 119 patients who met the eligibility criteria and who had completed
the questionnaires, 64 (54%) completed the first follow-up (fourth treatment) and 15
(13%) completed the second follow-up (eighth treatment). Assuming all the missing data
was of pain deteriorated cases, we found that the success rate of worst and average pain
improvement (at least 1 unit reduction in pain score) were 34% (95% CI: 25%, 43%) and
30% (95% CI: 22%, 38%) respectively. Among 64 patients who had completed the first
follow-up (using available data), the success rates were 63% (95% CI: 51%, 75%) and
55% (95% CI: 43%, 67%) respectively. The success rates that we found in this study
were a bit lower than our hypothesized value (at least 50%) if the most conservative
estimation is taken into account.
Based on available data, the mean improvement of worst and average pain were -1.09
(95% CI: -1.69, -0.50) and -0.86 (95% CI: -1.40, -0.32) respectively at first follow-up.
And they were -2.33 (95% CI: -3.85, -0.81) and -1.93 (95% CI: -3.31, -0.55) respectively
at second follow-up. Compared to several high quality acupuncture RCT treating chronic
low back pain, our results were slightly less important than the acupuncture effect
measured in these studies. This maybe due to the fact that there were more treatments (12
or more sessions) in the acupuncture studies compared to our study (8 sessions). Also,
patients involved in clinical trials tend to show higher improvements in response due to
the fact that they are being studied. Besides, positive bias may occur when we have
practitioners who are likely to bias in favour of needling technique to carry out their own
trials.
Other results regarding disability and quality of life items on Brief Pain Inventory (BPI)
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also showed improvement. And we found that most of the patients who completed the
first follow-up questionnaires (about 90%) were satisfied with IMS treatment. Regarding
logistic regression model to predict worst and average pain improvement, we did not find
any predictors associated with pain improvement, except initial pain score. However, this
may be due to a regression to mean phenomenon. Another interesting finding was that
practitioners may lead to different treatment outcomes. This raised the issue of possible
lack of consistency among IMS practitioners in treating patients. Therefore, we decided
to conduct an inter-rater reliability test before the set up of RCT.
Study 3: Inter-rater Reliability Test
This study consisted of 20 patients and 5 practitioners (raters). Examination focused on
lower back and lower limbs. Regarding the consistency in identifying number of taut
bands in paraspinal muscles along the spine, the intra-class correlation coefficient (ICC)
was 0.66 and 0.68 in thoracic segments and lumbar segments respectively. Regarding the
consistency in identifying number of taut bands in back, hip, thigh and leg regions, the
ICC varied from 0.64 to 0.77. Regarding the consistency in identifying taut bands in each
muscle, multiple raters kappa values ranged from -0.05 (poor agreement) to 0.46
(moderate agreement). Lastly, the consistency of identifying autonomic dysfunction was
also low, with multiple raters kappa ranged from -0.16 to 0.20 (poor agreement). The
reliability of identifying number of taut bands met our study hypothesis (ICC of 0.6), but
the reliability of identifying taut bands in each muscles did not meet our hypothesized
value (kappa of 0.6). The great discrepancy among practitioners in identifying taut bands
in each muscle and autonomic symptoms raise concerns that practitioners may treat
patients differently. However, substantial consistency was obtained in identifying number
of taut bands along the spine and in different body regions. Therefore it may also possible
that different practitioners identified the same problem but had difficulties to relate the
myofascial pain symptoms to precise muscles. Other reasons leading to the poor
consistency obtained in this study include the practitioners’ self confidence to rely on
their own clinical experience rather than standard training practice; practitioners’ fatigue
in examining 20 patients in a few hours; and the large number of variables to record
during a short period of time.
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7.3 Conclusion from the Three Studies
The two chart reviews showed positive results regarding IMS in relieving chronic pain
and improving pain consequences. Although loss to follow-up was important (reflecting
usual practice), we believe that the success rate of pain improvement in the most
conservative approach is high enough to be considered given the difficulty in treating
chronic pain. Therefore, we suggest conducting a high quality RCT to further evaluate the
effect of IMS. The information obtained from the two chart reviews regarding population
characteristics and success rate of pain improvement will be used in justifying the type
and size of sample in the design of RCT. Good consistency among practitioners in
treating patients has to be achieved before the conduct of RCT. Therefore, we suggest
conducting another inter-rater reliability test. Before the start of another reliability test,
discussions among practitioners and comprehensive trainings for practitioners have to be
launched to ensure the standardization of clinical examination. Also, a new examination
form with fewer variables needs to be developed to avoid practitioners’ fatigue affecting
the consistency of the results.
7.4 Future Work: Conduct of RCT
According to what we have found in the review of literature (Chapter 2), most of the
published acupuncture trials involve the evaluation of traditional Chinese acupuncture
rather than that of dry needling of trigger points (TrP). We also found only two trials
assessing the difference in the effect of alleviating chronic pain between traditional
acupuncture and TrP needling, but the results were controversial. The existing evidence
shows that acupuncture is better than sham therapy in reducing chronic low back pain
only in the short-term, there is not enough evidence showing acupuncture is superior to
sham regarding intermediate and long-term benefits (Furlan et al 2005, Johnston et al
2008). The effect of TrP needling seems in the same range as the effect of TrP injections
(Cummings et al 2001). Evidence of TrP needling in alleviating chronic myofascial pain
when compared to sham is still limited. Regarding the efficacy of IMS, two RCTs
showed positive results, but limitation due to low methodological quality, small sample
size and no sham needling comparison (Ga et al 2007, Gunn 1980). Overall, it seems that
classic acupuncture and other needle therapies developed specifically to control
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myofascial pain may work to decrease chronic pain. However, there are only a few trials
of high methodological quality. Most of them are limited by: 1) small sample size; 2) lack
of concealment of allocation; 3) lack of long term follow-up; 4) no description of
co-intervention during follow-up periods; 5)inexperienced practitioners; 6)no
independent investigator; 7) no true sham therapy; and 8) lack of blinding or evaluation
of successful blinding.
Considering the need of more high quality trials with long term follow-up for both classic
acupuncture and TrP needling (including Ah-Shi acupuncture and IMS); and the lack of
evidence showing the differences in the needling effect against sham and among different
needling techniques, we propose to conduct a three-arm RCT with IMS, traditional
Chinese acupuncture and sham needling. Our study will be conducted by an independent
team of investigator with the participation of experienced acupuncturists and IMS
practitioners to reduce possible biases. We will assess the success of blinding patients at
the end of intervention. Furthermore, our study will provide long-term follow-up of
patients (1 year after the end of intervention). Long-term follow-up has always been an
issue in pain trials because patients withdraw participation and change their pain
medication over time; making trial results difficult or impossible to interpret. For instance,
the use of another analgesic or co-intervention that is superior to the study intervention
may have an effect on pain control. It is not possible to ask patients to keep the usual
treatment unchanged over time. Moreover, for ethical reasons, once proven efficacious in
the short term, all patients should have access to the study intervention. Therefore the use
of a classic outcome like “change of pain score over time” is not good for assessing the
long term effect of a pain intervention. This issue is not specific to the assessment of
needling therapies. None of the drug trials identified for treating chronic pain provide
answers regarding long term effect. A good outcome therefore should include both pain
intensity change and the use of medication. We then suggest the use of a “success/failure”
outcome where “success” defined as (i) pain score is decreased by 1 unit compared to
baseline assessment and (ii) the amount and types of analgesic drugs is the same or
reduced and (iii) no other pain management device or strategy has been used. Otherwise,
the intervention will be considered as “Failure”. Furthermore, loss to follow-up is a
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source of major problem that may lead to absence of long term assessment. Therefore, it
is suggested that investigators could often offer financial compensation to participants for
their time lost from participation (Grimes et al 2002). Apart from monetary reward,
incentives such as coupons, gifts or a price draw after each completion of follow-up
assessment are also recommended to keep patients’ participation throughout the study.
Methods of follow-up assessment should be convenient and easy to access. Web-survey
seems to be a good tool because patients can complete follow-up assessment whenever
they feel comfortable. In our proposed trial, follow-up assessment is conducted by
telephone which is easy and straight forward; we may also implement a web-survey as
another form of follow-up assessment. A diary can be provided to patients at the end of
the intervention to collect information regarding degree of pain, functional limitations,
use of pain medications and alternative treatments. We also recommend the use of BC
administrative databases with the profiles regarding drugs and other health services
before and after interventions. We thought that the use of administrative databases after
obtaining subjects’ comments could provide a good result of the long-term effect of
interventions. All these features are part of the RCT proposal which is presented in
Chapter 8 of this thesis. The proposal has been submitted to Canadian Institute of Health
Research (CIHR) in March 2010.
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CHAPTER 8: A Proposal for a Randomized Controlled Trial (RCT)
8.1 Title of the Study Proposal
Needle Therapy to Treat Chronic Myofascial Pain: Intramuscular Stimulation and
Traditional Chinese Acupuncture Against Sham Needle
8.2 Background
Chronic musculoskeletal pain is an important health problem, as it is difficult to treat, and
has huge consequences for the patients (source of disability, poor quality of life and
financial and emotional consequences) and society (substantial direct, e.g. healthcare and
indirect cost e.g. lost productivity) after the initial acute pain episode, an important
component that can lead to pain chronicity is the development of a myofascial pain
syndrome (MPS). Whatever the mechanisms of MPS development, once in place it has
a tendency to self maintain and most often it resists conventional treatments. In this
situation, patients try alternative treatments, especially needle therapy. A meta-analysis
showed that classic acupuncture (using meridian points) has some effects on reducing
pain in the short term. Other needle therapies such as intra-muscular stimulation (IMS),
based on a different pathophysiological model than acupuncture, also seem to be
beneficial for patients with chronic pain. However research in this domain, although
interesting, suffers from poor quality, thus results are not reliable. Our project is aimed
at comparing the respective effects of acupuncture and IMS to sham needle treatment for
controlling chronic pain. To keep focused, we decided to concentrate on chronic low
back pain (CLBP), because it is the most important debilitating chronic pain problem and
a well recognized societal burden worldwide. The review will first describe briefly the
problem of CLBP and will then explain the mechanism of chronic pain, through the
development of chronic myofascial pain. After a short review of conventional
treatments, this section will then describe the different types of needle therapies and will
present relevant study results. This whole section will serve as a rationale for our
project.
Low back pain (LBP), defined as pain located in the lumbar vertebrae area (Stephen
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2006), is a major public health and economic problem worldwide (Bernard 2005),
especially when it is chronic. In 2003, the World Health Organization reported lifetime
prevalence of LBP ranging from 50 to 80% (Hammill et al 2008, Woolf et al 2003). In
developed countries point prevalence varies from 12 to 37% (Gourmelen et al 2007,
Maniadakis et al 2000, Schmidt et al 2007, Walker 2000), with a peak prevalence
between age 45 and 65 (Church et al 2007, Devon 2007, Hammill et al 2008). Among
people with an acute episode of LBP, 60 to 70% recover within 6 weeks and 80 to 90%
within 12 weeks (Andersson 1999). For those individuals (10-20%) who do not recover
within 3 months the problem becomes “chronic” (Andersson 1999, Dworkin 2002,
Leclerc et al 2006).
Chronic low back pain (CLBP) is the most frequent condition leading to disability, work
loss, psycho-social problems, and impaired quality of life (Andersson 1998, Al Obaidi et
al 2003, Devon 2007, Hammill et al 2008, Keeley et al 2008, Marin et al 2006). Patients
experience difficulty with daily functions (lifting, dressing, washing). Other problems
include the inability to stand or sit comfortably and slowed walking compared to people
without back pain (Al Obaidi et al 2003, De Souza et al 2007). A survey in the UK (Dodd
1997) revealed that pain compelled 8% of back pain patients to spend at least one day
lying down in the preceding 4 weeks, and 30% to restrict their daily activities during the
same period . CLBP also greatly affects the quality of sleep; Martin et al showed that
over 90% of patients with CLBP had restless sleep and insomnia, a source of depression,
anxiety and stress (Keeley et al 2008, Marin et al 2006). As a consequence, their social
life is greatly affected with reduced leisure activities and social interactions, creating
social isolation (Keeley et al 2008). Of concern is that over 75% of patients with CLBP
suffer from at least one clinical or subclinical psychiatric disorder (depressive or anxiety
symptomotology) (Polatin et al 1993). Apart from affecting individuals’ health and
quality of life, CLBP is the most frequent cause of absence from work and workers’
compensations, creating an enormous economic burden on society (Andersson 1998,
Devon 2007, Maniadakis et al 2000). It is estimated that LBP contributes to 40 to 68% of
all lost work days (Andersson 1999, Manchikanti 2000, van Tulder et al 2002). In the
United Sates LBP causes approximately 175 million work days lost per year, with an
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estimation of USD$28 billion productivity loss annually (Rizzo et al 1998) and an overall
economic burden of over USD$40 billion in direct medical treatment, costs associated
with disability, and absenteeism from work (Andersson 1999, Hammill et al 2008).
Among LBP-related costs, the “chronic” pain patients are responsible for over 90% of the
total costs and utilize the majority of allocated resources (Furlan et al 2002). Similar
economic figures are found in the UK: £1.6 billion for direct medical cost, £10.7 billion
for informal care and disability and £9.1 billion related to work absenteeism (Maniadakis
et al).
Acute LBP commonly occurs in people who have predisposing factors such as obesity,
sedentary work, frequent heavy lifting, repetitive improper movement, or exposure to
vibrations (Andersson 1999, Church et al 2007, Devon 2007, Hoogendoorn et al 2000,
Stephen 2006, Wilder et al 1988). Specific conditions have been identified such as
direct trauma of the spine or the back, spinal disc degeneration, disc herniation,
spondylosis, osteoporosis, tumor infusion, virus infection, inflammation, and rheumatic
diseases (Church et al 2007, Hammill et al 2008, Ross 2006, van Tulder et al 2002).
However, in most cases (80-90%), due to weak associations among symptoms,
examination findings, and anatomic changes, a precise pathoanatomic cause cannot be
reliably confirmed by physical examination or diagnostic testing (Hammill et al 2008,
Wand et al 2008). A study of acute LBP by Deyo et a1 (1992, 2001) showed that 10%
was caused by degenerative disks, 4% by disc herniation, 4 % by compression fractures,
3% and 2% by spinal stenosis and spondylolisthesis, respectively, and about 2% in
relation to visceral diseases. The remaining cases were “idiopathic LBP”, due to
“non-specific” causes which could not be ascribed to a precise pathoanatomical cause
(Deyo et al 2001, van Tulder et al 2002, Wand et al 2008).
Many of the causes listed such as degenerative or herniated disc, spondylosis are
responsible for the development of radiculopathy due to nerve root impingement (Benoist
2002, Gorpille et al 1998, Rhee et al 2006). Disk disruption is considered the most
common cause of radiculopathy-induced LBP, with 98% involving L4-5 or L5-S1
interspaces (Frymoyer 1988). It occurs with sudden physical effort when the trunk is
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flexed or rotated (Borenstein 1996). Radiculopathy leads to nerve damage or dysfunction
which may account for the development of myofascial pain syndrome (see below).
The cause of chronic LBP following an acute episode of back pain is complex and not
completely understood. Some authors have proposed that the development of a chronic
myofascial pain syndrome in the follow up phase of an acute back pain episode may
account for a significant portion of ‘non-specific’ CLBP. It has been proposed that
myofascial pain syndrome (MPS) develops through two main mechanisms (primarily
muscular or secondarily to peripheral neuropathy) that may both be acting in the context
of acute back pain injury (see below). Independent of the pathways that operated
initially, once myofascial pain syndrome is in place it may persist and develop through a
self sustained process that it totally independent from the initial cause that lead to its
development; this cause may have actually disappeared at the time of chronic pain.
Next we will describe MPS signs and symptoms and explain the mechanism of
development that has been well documented.
Myofascial pain syndrome is characterized by muscles in a contracted state with
increased tone and stiffness, and that contain myofascial trigger points (Simons et al
1999). Myofascial trigger point (TrP) is defined as self-sustaining hyperirritable spot
located in taut band of skeletal muscle with zone of tenderness (Simons 1995, 1999).
Direct compression or palpation of TrP provokes a sharp contraction of muscle fibers that
induces radiating and aching type of pain into localized and referred area (Wheeler 2004),
with a strong patients’ reaction identified as “jump sign” (Gerwin 2001, Wheeler 2001).
Other TrP characteristics include muscle weakness, decreased work tolerance, limitation
of movement’s amplitude, impaired muscle coordination, stiff joints and fatigue (Friction
et al 1985). Signs of sympathetic activity are also frequent in the zone of TrP: abnormal
sweating (sudomotor reflex), decrease in skin temperature (vasomotor reflex),
goosebumps (pilomotor reflex), local skin oedema and some trophic changes such as
dermatomal hair loss and cracking nails (Baldry 2001, Borg-Stein et al 2002, Gunn, 2007,
Shah 2008).
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Pathophysiology of chronic myofascial pain development Myofascial pain develops
through two main pathways (muscular and neuropathic) that correspond well to the
clinical picture of patient with LBP and CLBP.
Research investigating myofascial pain shows that direct injury and mechanical stress on
muscle are the primary causes for myofascial pain (Baldry 2001). Trauma or abnormal
stress causes affected muscle fibers to release excess intracellular calcium. This abnormal
increase of calcium induces uncontrolled muscle fibers contraction, local circulation
impairment and increased metabolism, resulting in the formation of muscle contracture
(or taut band) and the activation of TrP (Hong et al 1998). Myofascial pain syndromes
may also develop as consequence of peripheral neuropathy, for instance a radiculopathy
in the context of a musculoskeletal disorder (Backonja 2003, Backonja et al 1998,
Dworkin 2002, Hansson et al 2001, Latov 2007, Wheeler 2004). Any nerve root lesion or
dysfunction at the level of the spine will lead to the development of peripheral
neuropathy within few weeks with hypersensitivity in the innervated striated muscle (of
neuropathic origin), creating muscular contracture (taut band) and TrP with referred pain:
a typical myofascial pain syndrome (Cannon et al 1949; Gerwin 2001).
Whatever the initial cause that leads to muscular contracture and TrP (muscular or
secondary to a neurologic component), the muscle tension abnormalities cause local
ischemia and the shortened muscles release endogenous substances such as bradykinin,
prostaglandins and serotonin. These substances activate muscle nociceptors which
cause deep muscle aching pain, muscle tenderness, muscle weakness and decrease in
range of motion (Mense 2003, Mense et al 2001, Galluzzi 2007). Furthermore, sensitized
muscle nociceptor endings release neuropeptides such as substance P and calcitonin
gene-related peptide (CGRP) which lead to a cascade of events including the release of
histamine, bradykinin, prostaglandins and serotonin (it is source of a self sustained
process). These cumulative effects create local edema in muscle tissue that affects local
circulation (Shah 2008). Furthermore, this rapid and intense discharge of sensory fibers
(sensory afferent barrage) activates sympathetic preganglionic neurons on reaching the
spinal cord and thus causes noradrenergic postganglionic neurons in sympathetic chain to
75
become activated. As a result, sympathetic efferent activity is being increased and causes
the release of norepinephrine which is responsible for the autonomic phenomena (Jay
1995, Baldry 2001). Other studies have shown that activation of sympathetic
preganglionic neurons participates in pain generation (Janig 1995, Janig et al 2001, 2003)
through secretion of nerve growth factor (NGF) which drives local inflammation
(Andreev et al 1995, Woolf et al 1996).
Apart from peripheral muscle nociceptor sensitization, central sensitization at the spinal
cord dorsal horn is also a factor in the myofascial pain mechanism (Hong et al 1998).
When peripheral nociceptors are sensitized by injured muscles as described above, the
high-threshold Group IV (C) afferents will fire at a lower threshold causing allodynia and
central sensitization at the dorsal horn (Hoheisel et al 1993). Central sensitization induces
deep somatic afferents to converge at synaptic connections with post-synaptic neurons at
the dorsal horn resulting in the phenomenon of referred pain (Vecchiet et al 1999, Bahr et
al 1981). It can also activate the release of substance P and N-methyl-D-aspartate
(NMDA) which further enhances the synaptic connections at dorsal horn. This may
account for the persistent pain when TrP is once activated (Shah 2008).
Few epidemiological studies document the high prevalence of myofascial pain syndrome
in the context of chronic pain and CLBP. Fishbain et al. (1986) showed that among 283
chronic pain patients admitted to a pain center, 85% had their pain related to myofascial
pain with TrP. Also, myofascial pain is frequently associated with chronic head, neck and
back pain (Borg-Stein et al 2002, Simons 1988). In a study of 164 patients referred to a
pain clinic with chronic head and neck pain, 55% were found to have myofascial pain
(Friction et al 1985). In another study, Weiner (2006) showed that among 131 chronic low
back pain patients, 95.5% of them had myofascial pain symptoms. Myofascial pain is
believed to be one of the most common chronic pain syndromes that leads to disability
and public health burden (Gerwin 2001, Weiner 2001).
Conventional treatments for controlling chronic myofascial pain: The American Pain
Society (APS) recommends tricyclic antidepressants, benzodiazepines, gabapentin, and
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opioids for severe chronic pain. However, clinical evidence demonstrated limited
long-term efficacy and patients commonly experience side effects such as addiction,
urinary retention, constipation, cardiac conduction block, dizziness, nausea, respiratory
depression and orthostatic hypotension (Gilron et al 2006, Abram 2006, Dworkin et al
2003, van Tulder et al 2002). A recent review of evidence from APS stated that
NSAIDs when compared to placebo showed significant difference in alleviating pain a
week after treatment (Chou et al 2007) with no sign of long term effects. For
benzodiazepines, a Cochrane review (2 high-quality trials) found tetrazepam to be
associated with a greater likelihood of pain relief (RR, 0.71 [95% CI, 0.54-0.93]) and
global improvement (RR, 0.63 [95% CI, 0.42-0.97]) compared to placebo, after 10 to 14
days (Cochrane Back Review Group 2003). A systematic review of antidepressants
against placebo (9 trials) found a standardized mean difference (SMD) of 0.41 (CI,
0.22-0.61) for pain relief (Salerno et al 2002). Finally, a Cochrane review of opioids
showed that tramadol was more effective than placebo for relieving pain SMD 0.71 (95%
CI 0.39-1.02) and improving function, SMD 0.17 (95% CI 0.04-0.30) (Deshpande et al
2007), in the short term. Most of pain studies have important limitations because it is
difficult to control for the use of co-medications and interventions to control pain. For
instance when the outcome is the use of a pain score, it is very hard to take into account
the use of co-interventions. Most of studies do not provide any intervention regarding
the way they handle this issue that affect deeply the result’s credibility. In our proposal,
we will use a “success-failure” outcome that enables integrating the pain score and the
use of co-intervention to determine “success”.
Complementary and alternative medicine (CAM): Due to lack of long-term efficacy and
potential adverse effects of conventional treatments, many patients use CAM. Official
guidelines also recommend their use (Chou et al 2007). Common CAM therapies for
chronic pain include exercise, spinal manipulation, massage, acupuncture, electrical
nerve stimulation, laser therapy and intramuscular stimulation. We will focus on needle
therapies and describe acupuncture and IMS deep needling therapy.
a) Traditional Chinese acupuncture is a dry needling technique that targets acupuncture
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points on well defined meridians, which emphasize a smooth flow of Qi (vital energy)
and homeostasis in human body. It has been practiced in China for thousands of years in
reducing chronic pain and started to draw attention to western countries in the past
decades. The acupuncturist after precise diagnosis of a TCM syndrome develops a
treatment strategy that includes treatment of specific acupoints on specific organ
meridians that circulate across the body and transfer energy (Qi) expressed through two
forms, yin or yang. According to this theory, pain is often considered as consequence of a
“Qi blockage”. The treatment strategy consists of use of needles to remove the
identified blockage. Recent animal studies documented acupuncture’s mechanism of
action. The needle activates proprioceptive Aβfibers which inhibit the input of small
nociceptive C fibers (Gate Control Theory) (Moffet 2006, Abram 2006). The needle also
stimulates Aδfibers which causes interneuron activation in the dorsal horn and the release
of endogenous opioids and neurotransmitters (serotonine, gama-aminobutyric acid and
acetylcholine), inhibiting intraspinal transmission of C fiber input (Moffet 2006, Cheung
et al 2001). Finally, recent studies showed that acupuncture can modulate the sympathetic
outflow and reduce sympathoexcitatory reflex responses (Li et al 1998, 2001, Dai et al
1992, Tjen-A-Looi et al 2003) with decrease of inflammation, thus reducing pain (review
by Longhurst 2004).
Clinical studies support the effect of acupuncture. One Cochrane review on chronic low
back pain (8 trials) showed evidence supporting the short-term pain relief (3 months or
less) and functional improvement of acupuncture, compared to no treatment or sham
therapy (Furlan et al 2005). Two high quality trials showed that acupuncture was more
effective than sham therapy with a weighted mean difference (WMD: sum of the
differences weighted by individual variances) of -1.78 (95% CI: -2.55, -1.07). However,
the pooled results (underpowered) from two high quality trials found that acupuncture
was not significantly better than sham therapy in terms of intermediate-term pain relief,
with a WMD -0.57 (95% CI: -1.47 to 0.33). Therefore, the conclusion stated the need
for high-quality trials to better document the short term effect of acupuncture and to study
long term effectiveness (Furlan et al 2005, Johnston et al 2008).
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b) Other forms of needle therapies are also used with reported effects on managing
chronic pain. We will describe here two techniques that use dry needles at points of
palpable tenderness located in contracted muscle (i.e. the taut band of myofascial pain
syndrome): “Ah Shi acupuncture” and Intramuscular stimulation (IMS). Ah-Shi
acupuncture (Birch 2003, Hong 2000, Shah 2008, Mense et al 2001) and IMS (Gunn
1997, 2007; Ga 2007) have been used extensively in the domain of CMP. In both
techniques practitioners insert needles into select contracted muscles. Needle in
contracted muscles works by creating a local twitch response in the muscle responsible
for an extra contraction of muscle fibers. This contraction sensitizes reflex motor efferent
activity or Golgi organs (proprioceptive sensory receptor organ that measures tension of
muscle contraction) causing reflex relaxation and, hence, pain relief (Gunn et al 1985,
Baldry 2001). In addition, the needle also activates all the mechanisms associated with
classic meridian based acupuncture (described above). The main difference between Ah
Shi acupuncture and IMS is the pathophysiological principles on which each is based.
IMS considers that CMP is the consequence of peripheral neuropathy (mostly a
radiculopathy in the context of low back pain) (Gunn 1997, 2007). The technique
employed in IMS acupuncture is similar to that in Ah-Shi acupuncture, (practitioners
insert needles deeply into contracted muscles), but treatment is applied to all associated
spinous muscles at segmental levels according to the mechanism of an underlying
pepipheral neuropathy. IMS theory is based on the fact that TrP and taut band at limbs
and trunk are closely associated with the segmental distribution of lumbar radiculopathy
at the back (Gunn 1997). When IMS practitioners treat chronic myofascial pain, they
search carefully for the TrP and taut band, as well as signs of peripheral neuropathy
(autonomic symptoms for instance) and apply IMS treatment specifically on the regions
of muscular contractions to induce the relaxation reflex (Gunn 2007). IMS may alleviate
pain through three different mechanisms: (a) by relaxing contracted muscles; (b) by
decreasing C fiber ectopic impulses from the injured nerve and (c) by inhibiting the
sympathoexcitatory reflex (similar to acupuncture).
Literature review regarding Ah-Shi acupuncture and IMS are poor and not conclusive. 1)
We only found two small sham controlled studies assessing the effect of Ah-Shi
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acupuncture; and we found several studies and one systematic review (Cummings et al
2001) comparing the respective effects of dry needling at TrP and injections of local
anesthetic or botulinum toxin. The review reports that after the immediate effect of
local injection (i.e. one week after the intervention), the trends observed support a
possible effect of a dry needle intervention in the range of those observed with local
injections. The authors strongly recommend conducting high quality trials against sham
control, with sufficient power and enough duration (Cummings et al 2001). 2) Two
studies have been conducted to assess IMS efficacy. Ga et al (2007) showed that among
43 patients with chronic MPS in the upper trapezius muscle, IMS was equivalent in
reducing pain intensity to lidocaine 0.5% injection at 1-month follow-up. An unblinded
trial by Gunn (1980) involved 53 patients with chronic low back pain. Both treatment and
control groups followed a standard regimen of physiotherapy, remedial exercises and
occupational therapy while subjects in treatment groups also received IMS twice a week.
In the IMS treatment group 62% of patients returned to their original work and 34%
shifted to a lighter employment while in the control group only 15% of patients returned
to their original work and half of these worked in a lighter employment. In the last 12
months we conducted a cohort study of all patients treated by IMS at one clinic in
Vancouver. We found that the success rate (at least one point deduction in 0-11 average
pain scale) was 55% for patients who had received their fourth IMS treatments and the
mean change in worst pain score was -1.09 (95% CI:-1.69, -0.50). We have also
conducted an inter-rater reliability test to test the consistency among IMS practitioners in
identifying taut bands, good consistency was found in identifying the number of taut
bands at spine levels; we are still working with the team to improve diagnosis consistency.
Despite absence of solid evidence, the IMS technique is widely used in Canada and
worldwide for treating myofascial pain and neuropathic pain. Because IMS therapy
takes a broader approach than Ah-Shi acupuncture (by treating spine segmental level)
while sharing the same technical approach, we decided to use IMS as second intervention
in our project to compare it to acupuncture and sham needling.
8.3 Rationale
Overall, CLBP is an important health problem; difficult to treat and responsible for an
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enormous burden for patients and society. There is evidence that classic acupuncture
and other needle therapies developed specifically to control myofascial pain may work to
decrease pain in CLBP patients, but these techniques have not been compared against
each other and they both still need to be compared to sham treatment to assess clearly the
importance of the effect and its duration. Our proposal aims to compare the
effectiveness of classic acupuncture and IMS needle therapy against sham needle, for
pain management. Because our project is conducted by an independent team of
investigator with the participation of excellent acupuncturists and IMS practitioners, it
represents a unique opportunity to provide an answer to this important question that has
significant public health implications. Other features of our proposal are a) the use of a
“success-failure” outcome that is more likely to generate valid results and b) long term
follow-up using administrative databases.
8.4 Clinical Relevance
The trial results, either positive or negative, will be useful to inform patients and
practitioners. If the results are positive regarding IMS or acupuncture against sham,
more patients may then look for these treatments and get benefits. If the results are
different between IMS and acupuncture, in particular with regard to the presence of
chronic myofascial pain syndrome, the information will be very useful to guide patients.
Positive results may also lead to the development of a stronger research stream in a very
important domain of therapeutic care that is frequently used by patients, and remains
largely neglected by researchers. If the results do not show any benefit above sham
needle, this information will also be useful to publish to inform practitioners and patients.
Trial results therefore, whatever the results’ direction will be published in peer review
journals and also in large public dissemination journals. Diffusion will include
interviews and media presentations (radio and TV). Scientific results will be presented
at the Canadian Pain Society and other International societies. These societies are well
attended by pain specialists and also by patients. Presenting results in public forums
will have a large impact for the diffusion of the results. Dr M Chung will practice
acupuncture in our study; as VP of the BC College of Chinese Medicine and Acupuncture
he will facilitate the diffusion of the results in the community of acupuncturists in BC and
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Canada,
8.5 Study Objectives
Primary objective is to assess whether IMS or acupuncture intervention demonstrates
greater benefits than sham needling in reducing pain intensity in patients with chronic
low back pain 6 months after the end of the intervention.
Secondary objectives are 1) to assess whether IMS or acupuncture intervention can
decrease the consequences of chronic low back pain on disability and quality of life
compared to sham needling; 2) to compare the effect of IMS and acupuncture
intervention in reducing pain and pain consequences; 3) to study the effect of the two
needling strategies up to 12 months after the end of the intervention.
8.6 Study Hypothesis
We expect both IMS and acupuncture showing more benefits in reducing chronic pain
compared to sham acupuncture. We expect the effect size of IMS in reducing pain
intensity to be higher than that of acupuncture.
8.7 Study Design
This is a single (subjects) blind RCT and it is conducted by a research team that is
independent from the clinicians who practice IMS or acupuncture. Participants with
CLBP, who meet the inclusion and exclusion criteria, will be recruited and randomly
allocated to IMS, acupuncture or sham acupuncture. Interventions will be carried out
once or twice a week for a maximum of 8 weeks and 12 sessions. This combination of
fixed time for the intervention (8 weeks) and up to 12 sessions has been decided after
discussion with the needle specialists as covering all situations in which effect will be
observed; following longer and offering more sessions is possible – but it is for cases that
are relatively resistant to the treatment. Baseline full assessment will be conducted
before the first intervention and the same assessment will be conducted at the end of the
study intervention (after 8 weeks) or whenever subjects to interrupt the treatment. The
long term effect will be assessed by phone interviews conducted 3, 6, 9, 12 months after
the study intervention. Long term effect and overall impact on health services use will be
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assessed using BC administrative databases. During the intervention period, subjects
will also undergo simple pain intensity assessment before each new session. All
assessments will be conducted by a research team member who is unaware of the nature
of the intervention.
8.8 Sample Specification
Our target population is subjects with CLBP defined as pain and muscle tension/stiffness
located in the lower lumbar spine corresponding to L1 and below. In practice: below
costal margin and above the inferior gluteal folds (Dworkin 2002, Stephen 2006, van
Tulder et al 2002) that persisted for at least 6 months. We will consider that duration is
≥ 6 months if, at the time of inclusion the date of the first pain treatment is ≥ 6 months
AND there has been no period longer than 1 month without pain in the same area. Age
lower limit is 18 years without upper limit.
Exclusion Criteria:
Patients with low back pain of less than 6 months duration
If the “Average Pain” on the Brief Pain Inventory scale is < 4 at inclusion
Patients who have pain from other origins: spinal cord injury, rheumatic disease,
fibromyalgia, neuropathic pain from central origin. Patients with “secondary”
myofascial syndrome due to serious diseases (like cancer, metabolic disease,
diabetic neuropathy)
Patients who received IMS or acupuncture treatment previously for the same reason
Patients who are off work for over 3 months due to injury, those receiving disability
payments
Patients who have serious bleeding tendencies
Patients with another serious condition that may (a) interfere with normal follow up
(eg. cancer, serious kidney disease, Alzheimer Disease), (b) be the source of pain (eg.
severe migraine) or (c) may affect quality of life or be source of disability (eg.
Parkinson Disease).
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8.9 Interventions
8.9.1 IMS Intervention
IMS is administered by certified IMS practitioners. Sterile stainless steel acupuncture
needles are used and are not re-used. 30 gauge or finer needles are used depending on
severity of muscle contraction. Needles are mainly 2-3 inches in length. Needles are
deeply inserted into muscle taut bands and associated spinous muscles along the spine.
Needles will remain in the muscle for 10 to 20 minutes and will be twisted from time to
time to induce the reflex.
8.9.2 Acupuncture Intervention
Acupuncture is performed by certified acupuncturists. Sterile stainless steel acupuncture
needles are used and are not re-used. 30 gauge or finer needles are used depending on
severity of muscle contraction. Needles are mainly 2-3 inches in length. Needles are
deeply inserted into acupoints on meridians BL, GB and KI that are often applied in
treating low back pain. In our study, needles will remain in place for a similar amount of
time to that of IMS intervention and all practitioners will be trained to provide the same
type of care to all patients.
8.9.3 Sham Intervention
The control for acupuncture will be placebo acupuncture needle designed and published
by our collaborator Takakura of the Japan School of Acupuncture, Moxibustion and
Physiotherapy at Hanada College. The placebo needles are shorter and blunt versions of
acupuncture needles approved for sale and readily available in Canada. Guidelines are
in place to ensure quality and sterilization in accordance with Good Manufacturing
Procedure. Two validation studies have been conducted and published for these placebo
needles. Of the 120 needles (60 real needles, and 60 placebo needles), the patients
identified 65(54.2%) correctly (penetrating needle = 35, non-penetrating needle = 30) and
55 (45.8%) incorrectly (penetrating needle = 25, non-penetrating needle = 30), which fits
a probability of 0.5 (χ2 = 0.833, p = 0.361) (Takakura et al 2007, 2008). Further
validation test will be conducted at the end of this study by surveying the subjects’
opinions of which intervention groups they have been assigned to. In our study, needles
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will remain in place for a similar amount of time to that of IMS and acupuncture
intervention and practitioners will be trained to provide the same type of care to all
patients.
8.9.4 Co-medications and Complementary Interventions
During the study, all subjects will be informed (a) to undergo periods of stretching twice
a day – according to precise instructions (b) to keep their drug treatment stable, (b) to not
add any new drugs, and (c) to not use other alternative medicine. This information will
be collected regularly during the trial and used in the analysis.
8.10 Allocation of Intervention
8.10.1 Methods for Randomization and Stratification
Participants who meet the inclusion and exclusion criteria and who have signed the
consent form will be randomized after recording baseline information. Randomization
will be stratified based on intensity of the myofascial pain syndrome (number of TrP </=
3 or >3) and duration of pain (6 months to 2 years or >2 years). Subject allocation will
be based on sequence of computer-generated random numbers with blocks of size 3 to
control tightly the allocation balance within each stratum. Access to the randomization
list will be through a web-based system that enables online interactive checking of the
inclusion/exclusion criteria before authorizing random allocation. The trial coordinator
will initiate the randomization process and transmit the information to the practitioners
who conduct the intervention.
8.10.2 Methods for Minimization of Bias
Randomization and concealment of allocation protects against selection bias. Blinding
patients and interviewers to the nature of the intervention ensures protection against
performance and detection biases. Practitioners cannot be blind; however, (a) they will
not be involved in collecting information from patients and (b) they will be trained to
provide the best care to all patients: interaction, discussion, explanation and needling
duration (the duration of the intervention will be monitored). All patients will be treated
in one clinic – therefore, after randomization subjects will go with the practitioner who is
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in charge of the intervention. Sham acupuncture will replicate the IMS needle.
Results of physical examination and strategic treatment plan will be recorded. The
whole process of making diagnosis and developing IMS treatment strategy has already
been assessed and showed very good consistency at segmental level and we are working
with team to increase consistency at muscular level. Interviewers from the research
team will be blinded to avoid any detection bias. They will use standard questionnaires
and adhere to strict interview processes. Attrition bias is protected by telephone contact
that minimizes loss-to-follow-up. Moreover, use of administrative databases will help
organizing long term follow-up in a rigorous and unbiased manner. The
lost-to-follow-up procedure will involve phoning patients who fail to attend a session or a
follow up visit, to determine the reason and to collect minimum information regarding
pain intensity (primary outcome). During the study patients will be asked not to try
acupuncture or other types of complementary medicine (TENS, massage) and to keep
their drug treatment stable; drug use and co-interventions will be recorded precisely at
each treatment visit.
8.11 Treatment Duration
The duration of the intervention may vary from one patient to another in relation to the
treatment efficacy – for a maximum of 12 sessions, offered during an 8 week period.
Treatment is interrupted when pain disappears or when patients and practitioners do not
see any improvement after three consecutive sessions (criterion for the study) because the
maximum gain is considered to have been achieved. The maximum treatment duration
for this study will be 8 weeks with one to two sessions per week (8 to 12 needle sessions).
If patients have to leave the study for one week or two, the time lost will be recuperated
when they return to accommodate the 12 sessions.
8.12 Frequency and Duration of Follow-up
Follow-up will start at the end of the treatment period: patients will be examined and
interviewed at the end of the intervention (8 weeks for most patients); they and will be
interviewed by telephone at 3-month, 6-month, 9-month and 1 year after the end of
interventions. The whole set of outcomes (type of pain, disability and quality of life)
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will be assessed at each follow-up contact. A diary will be given to the patients at the end
of the intervention to collect information regarding degree of pain, functional limitations,
use of pain medications and alternative treatments. We will also use administrative
databases to compare the use profiles regarding drugs and other health services
(physiotherapy, medical consultation) before and after interventions in the three groups.
8.13 Outcome Assessment
8.13.1 Types of Outcomes
The primary outcome will be assessed 6 months after the end of intervention using a
“Success-Failure” outcome that includes information on pain control and the use of
co-interventions. “Success” will be defined for each patient if (i) average pain score (BPI
scale) is decreased by 1 unit compared to baseline assessment and (ii) the amount and
types of analgesic drugs is the same or reduced and (iii) no other pain management
device or strategy has been used. Otherwise, the intervention will be considered “failure”.
Acupuncture and IMS consolidation treatment after the 8 week intervention is expected
and will be recorded – it will not considered a treatment failure. For the intention to
treat analysis, patients who do not complete follow-up will also be considered “failure”.
The Brief Pain Inventory (BPI) will be used to assess pain; this scale is the most widely
used to assess severity and impact of pain on daily function (Cleeland et al 1994). Each
question is measured on a numerical rating scale ranging from 0 (no pain at all/no
interference) to 10 (pain as bad as you can imagine/complete interference). BPI has been
validated for the consistency, reliability and sensitivity of severity of pain and impact of
pain. We will use BPI-Q1 “Average Pain in the last week” for the determination of
“success” the primary outcome because it is the most relevant question for people who
suffer from chronic pain.
Secondary outcomes include other measures of pain (i.e. other pain scales in BPI), pain
consequences (disability, quality of life) and adverse events:
a) Other pain intensity scales on BPI include “Worst pain in last weak”, “least pain in
the last week”, and “pain right now”.
b) Question 5 of BPI assesses the level of pain interference in seven domains: general
activities, mood, walking ability, normal work, relations with other people, sleep and
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enjoyment of life. Each question is measured on a numerical Likert rating scale
ranging from 0 (no pain at all/no interference) to 10 (pain as bad as you can
imagine/complete interference).
c) Change in disability will be assessed using the Oswestry Low-Back Pain Disability
Index (ODI) (Fairbank et al 1980). The ODI consists of ten questions on activities of
daily living which include personal care, lifting, walking, sitting, standing, sleeping,
sex life, social life and traveling. It is one of the most commonly used questionnaires
to assess degree of disability for back pain and has demonstrated good reliability,
validity, and responsiveness (Fairbank et al 1980, Kumar et al 2007, Turk et al 2001).
Among all randomized controlled trials that evaluate LBP, nearly 59% of them use
ODI to assess the disability functioning of LBP patients (Hammill et al 2008).
d) Change in quality of life will be assessed using Medical Outcomes Study 36-Item
Short-Form Health Survey (SF-36v2) (Ware et al 1993). SF-36v2 is a well-validated
measure of generic quality of life that has been used extensively in many conditions,
including chronic pain. It has eight subscales that can be analyzed separately
(physical functioning, role physical, bodily pain, general health, vitality, social
function and role emotional) and two summary scales: Physical and Mental.
e) Change in anxiety and depression will be assessed using the Hospital Anxiety and
Depression Scale (HADS). HADS has been widely used worldwide. Its psychometric
qualities have been documented in both hospitalized and primary care patients and in
the general population (Bjelland et al 2002, Herrmann 1997). The HADS consists of
fourteen questions, seven to derive an anxiety score (HADS-A) and seven to derive a
depression score (HADS-D). Scores can be interpreted as follow: 0-7 normal, 8-10
=borderline/mild, 11-14 =moderate, and 15-21 =severe (Schipper et al 1990). It will
be used as an outcome (because reduction of pain should improve depression) and
also as a predictor as patients with depression may have more difficulty to improve.
f) Use of drugs and health services by patients before the intervention and after is an
important objective outcome to assess the overall effect of the intervention. British
Columbia has an excellent set of databases to describe drug prescription (Pharmanet)
and use of health services (Medical Service Plan data base (MSP). The primary
investigator (JPC) has already been funded by CIHR (PI is S Amed) for the use of
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these databases to assess quality performance in treating diabetic patients in BC (June
2009; #193166).
g) Adverse events (AE) will be recorded systematically on a weekly basis when patients
attend the treatment sessions using standard AE drug trials form. Serious adverse
events will be recorded and described according to special procedures.
8.13.2 Methods of Outcome Assessment
Outcome measurement will be made by research team members who do not know the
treatment allocation and are well-trained to keep the standard of interview homogeneous
which minimizes detection bias.
The whole set of outcomes (pain intensity, disability, quality of life) will be assessed at
baseline and at the end of treatment (whenever it happens). It will also be assessed at
3-month, 6-month, 9-month and 1 year after the termination of treatment by telephone
interview. During the treatment period, pain intensity will be assessed by interview before
each treatment session (short assessment using BPI). A diary will be given to the patients
at the end of the intervention to help keeping track of adverse events and pain
management strategies. Patients who fail to attend a treatment session and those who do
not come to a visit will be contacted by phone to reschedule an appointment or, if patients
cannot come, to collect the minimum useful information regarding the main outcomes
and the reason for not attending the scheduled visit. Information from BC
administrative databases will be related to drug and other health services use.
8.14 Recruitment
Recruitment should not be a problem because chronic low back pain is a frequently
occurring condition and the sample size is not too large. Patients will be recruited from
several pain clinics in Vancouver (each of them has an acupuncturist) and through
newspaper advertisement. All pain clinics have a long list of patients waiting to see the
clinicians; they also have a list of patients whose pain does not improve despite all
conventional treatments: We will try to have access to these populations. Interested
patients will receive a consent form and will be given enough time to decide upon
participation. After signing the consent form patients will be examined to confirm the
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diagnosis and verify all eligibility criteria. Patients who meet the study inclusion criteria
will then be randomized to one of the three groups.
8.15 Retention Strategy
Some people may limit the number of insertions during a treatment session due to initial
pain associated with insertion into contracted muscles. We will keep close contact with
patients who come once a week at the clinic during the treatment phase to keep
compliance and may adjust number of insertions. Also, patients will receive travel
compensation and free parking when they come to receive treatments. Follow-up
assessment is conducted by telephone which is easy and straight forward. Patients who
discontinue follow-up will be considered “failure” for the main outcome. Finally using
administrative databases is a very secure way to guarantee systematic follow-up of all
patients included.
8.16 Sample Size
We estimated the acupuncture effect size from several good quality studies comparing
acupuncture to sham needles (Kerr et al 2003, Leiging et al 2002, Mendelson et al 1983,
Molsberger et al 2002): WMD of pain improvement was 1.02 with standard deviation
around 2.5. We then considered that about 15% of patients in the sham treatment group
would meet the “success” criterion. If the success rate in the intervention groups is 45%
we need to include 43 patients in each group to have 80% power to find such a difference
significant (alpha=0.025). 55% success is the rate we found after one month of
treatment by IMS practitioners. Considering possible 10% withdrawal, total of 150
patients will be involved (50 in each arm). Such a sample size gives comfortable power
to assess all the continuous outcomes variables (mean differences in pain score, disability
or quality of life).
8.17 Statistical Analysis
Initially, we will examine the distributional characteristics of all variables graphically and
provide basic summary statistics. Analysis will be based on intention to treat approach.
The primary analysis will be the comparison between number of success and failure
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using chi-square test. Logistic regression will also be used to adjust for important
covariates (such as: initial pain score, duration of pain, gender, drug medications).
Secondary analysis will be on comparing the changes in pain intensity between groups at
baseline and follow-up (Average Pain, Worst Pain). T-test will be used for all
continuous variables and then the analysis of covariance (ANCOVA) model to adjust for
important covariates. Other pain questions will also be studied (e.g. Least Pain during
last week) and the analysis will take into account the multiple outcomes to prevent false
conclusion: p-values will be adjusted and results will mention the number of outcomes.
Note the sample size calculation already takes into account the fact that two active
treatments will be compared to one sham intervention through the use of Bonferroni
correction. To accommodate loss to follow-up, we will model serial measurements
using a linear mixed model approach. The model will include some baseline variables
which are clinically relevant or which show association with the occurrence of
incomplete follow-up, as per current recommendations (Geert et al, 2004). Side effects
will be described (organ classification) and comparisons will be made between groups.
Per protocol analyses will also be conducted after eliminating subjects who used
co-medications, or provided incomplete follow up. Along this line, sensitivity analyses
may be conducted to assess the impact of missing information according to different
scenario. Subgroup analyses will be exploratory to check possible difference in effects
according to previous duration of pain, gender, and number of segments involved.
8.18 Trial Management
8.18.1 Initiating Interventions Strategy
All interventions will take place at one clinic. As a block of size 6 will be used in subject
allocation in this study, interventions will start whenever there are 6 patients enrolled in
the study. IMS practitioners, acupuncturists and sham needling practitioners will then be
notified the date of intervention. At the clinic, each patient will receive intervention in a
closed room where there is only the patient and practitioner present in the room. Patients
will finish questionnaire in a waiting area with the presence of research coordinator who
is unaware of subject allocation. After each intervention, patients will be asked to come
again to receive the next session of intervention in the subsequent week until the end of
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all sessions. Time can be scheduled with practitioners whenever they are free to come to
the clinic.
8.18.2 Data Collection and Management
The trial will be managed by the Clinical Research Support Unit at BC Children’s
Hospital that has huge experience in conducting clinical trials with full respect of ethics
and regulation regarding confidentiality and privacy and ICH-GCP guidelines. This
team has already conducted intervention on traditional Chinese medicine. Initial contact
with patients will be made at the pain clinic and, if interested they will contact the study
coordinator who will share time between BC Children’s Hospital and the study site (one
acupuncture clinic); she will inform patients and collect consent. She will then
randomize patients using the Dacima on line system and organize the intervention.
Baseline and post intervention assessments will be organized by the coordinator using
questionnaires that most patients can complete without help after careful instructions.
Telephone interviews will be collected by the research coordinator at specific time.
Information will be entered (double entry procedure) into the electronic system with
online edit check and quality control. Quality assurance will also be reinforced using
automated real time reports (meta-data) to help managing the study and identifying
problems in a timely way. Database will be located on a server at the Research Institute
with high level protection and restricted access to the research team only. All
information and questionnaires will be stored in a locked filing cabinet. Study audits
will be conducted regularly to ensure full respect of protocol throughout the study. A
steering committee involves all co-applicants as well as the data Manager at BCCH and
the research coordinator. Adverse events will be recoded according to specific
procedures; the Principal Investigator will review them regularly and present them to the
Steering Committee.
8.18.3 Safety Monitoring and Adverse Events
IMS is a safe intervention. Patients may experience feeling of pain as needles inserted to
muscle trigger points and they may bleed a little at the needle insertion points (White et al
2001, Ernst et al 2001). Side effects will be reviewed regularly by the Principal
92
Investigator and presented to the Research Committee. Serious Adverse Event (SAE) will
be recorded and reported according to GCP standard procedures, decision of code
breaking will be determined by Principal Investigator.
8.18.4 Role of Principal Applicant and Co-applicant
Principal applicant, Dr Jean-Paul Collet, is professor of Pediatrics and Epidemiology at
UBC. He has huge experience in conducting clinical trials and has published several
articles regarding neuropathic pain. Dr Collet will oversee the whole study, ensuring strict
adherence to study procedures and making daily management decisions. Dr Millan Patel,
though he has no direct expertise in pain research, will contribute his thorough
knowledge of the sympathetic nervous system (SNS). He has extensive experience
studying the SNS in mice through genetic, pharmacologic and anatomic means. Dr Marc
White is the founder and executive director of the Canadian Institute for the Relief of
Pain and Disability (CIRPD). CIRPD will assist with patient recruitment. Dr White’s
academic focus is on knowledge translation and knowledge mobilization and will assist
with dissemination activities congruent with the importance of the findings. Dr Rollin
Brant is a senior statistician and professor in the Department of Statistics at UBC. His
collaboration as a biostatistician is critical for the analysis and will help in making
important decisions. All co-applicants will be responsible for reviewing protocol and
reports. Our team also includes experienced acupuncturist (Dr M Chung from the
College of acupuncturist and Chinese medicine in BC) and IMS practitioners (Dr Gunn
and Dr Lam) which is essential for the success of the study.
8.18.5 Steering Committee
The trial steering committee involves all co-applicants as well as the data Manager at
BCCH: Victor Espinosa and the research coordinator. There is no data safety and
monitoring committee in this study but the adverse events will be recoded according to
specific procedures and the Principal Investigator will review them regularly and present
them to the Steering Committee.
93
8.19 Ethics
This study proposal and all study related materials including consent forms,
questionnaires will be submitted to UBC Clinical Research Ethics Board for ethical
approval.
8.20 Budget
The budget for the first year study is estimated to be CAD$116,100.
94
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APPENDIX A: ADDITIONAL TABLES
Innervating segments in upper extremity muscles Innervated Muscles Segmental Levels
abductor brevis C6 C7 C8 T1 abductor digiti minimi C6 C7 C8 T1 abductor pollicis C6 C7 C8 T1 adductor pollicis C8 T1 biceps brachii C5 C6 brachialis C5 C6 brachioradialis C5 C6 coracobrachialis C5 C6 C7 C8 deltoid C4 C5 C6 C7 dorsal interossei C8 T1 extensor carpi radialis C5 C6 C7 C8 extensor carpi ulnaris C6 C7 C8 extensor digiti minimi C6 C7 C8 T1 extensor digitorum C6 C7 C8 extensor indicis C6 C7 C8 T1 extensor pollicis brevis C6 C7 C8 extensor pollicis longus C6 C7 C8 T1 flexor carpi radialis C6 C7 C8 flexor carpi ulnaris C7 C8 T1 flexor digiti minimi C6 C7 C8 T1 flexor digitorum C6 C7 C8 T1 flexor pollicis brevis C6 C7 C8 T1 flexor pollicis longus C6 C7 C8 T1 infraspinatus C4 C5 C6 latissimus dorsi C6 C7 C8 levator scapulae C3 C4 lumbricales C6 C7 C8 T1 opponens digit minimi C7 C8 T1 opponens pollicis C6 C7 C8 T1 palmar interossei C8 T1 palmaris longus C6 C7 C8 T1 pectoralis major C6 C7 C8 T1 pectoralis minor C8 T1 pronator quadratus C6 C7 C8 T1 pronator teres C5 C6 C7 rhomboid major C4 C5 C6 rhomboid minor C4 C5 C6 serratus anterior C5 C6 C7C8 supinator C5 C6 C7 supraspinatus C4 C5 C6 teres major C5 C6 C7
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Innervating segments in upper extremity muscles (continue) Innervated Muscles Segmental Levels
teres minor C4 C5 C6 C7 trapezius C3 C4 triceps brachii C6 C7 C8
Innervating segments in lower extremity muscles Innervated Muscles Segmental Levels
adductor brevis L2 L3 L4 L5 adductor longus L2 L3 L4 adductor magnus L2 L3 L4 L5 biceps femoris L4 L5 S1 S2 S3 dorsal interossei S1 S2 extensor digitorum brevis L4 L5 S1 S2 extensor digitorum longus L4 L5 S1 S2 extensor hallucis brevis L4 L5 S1 S2 extensor hallucis longus L4 L5 S1 S2 flexor digitorum brevis L5 S1 flexor digitorum longus L4 L5 S1 S2 S3 flexor hallucis L5 S1 gastrocnemius L4 L5 S1 S2 S3 gluteus maximus L4 L5 S1 S2 S3 gluteus medius L4 L5 S1 S2 gluteus minimus L4 L5 S1 gracilis L2 L3 L4 L5 pectineus L2 L3 L4 peroneus brevis L4 L5 S1 S2 peroneus longus L4 L5 S1 S2 piriformis S1 S2 S3 quadratus femoris L4 L5 S1 rectus femoris L2 L3 L4 L5 sartorius L2 L3 L4 semimembranosus L4 L5 S1 S2 S3 semitendinosus L5 S1 soleus L4 L5 S1 S2 S3 tensor fascia lata L4 L5 S1 tibialis anterior L4 L5 S1 S2 tibialis posterior L4 L5 S1 S2 vastus lateralis L2 L3 L4 L5 vastus medialis L2 L3 L4 L5 vastus intermedius L2 L3 L4 L5
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APPENDIX B: HUMAN ETHICS APPROVAL CERTIFICATE
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