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SS/EBM/IKA-UDIP-2010
(”Bringing research evidence
into practice”)
Evidence-Based Medicine
Sudigdo Sastroasmoro
Clinical Epidemiology and Evidence-based Medicine Unit
FMUI – CMH, Jakarta
SS/EBM/IKA-UDIP-2010
Evidence-based Medicine
• Medicine-based evidence
• Pragmatic research
• Outcome research
Related with
morbidity, mortality, quality of life
SS/EBM/IKA-UDIP-2010
Value = Quality
Cost
Morbidity
Mortality
QoL
Patient
Satisfaction
Health
Status
SS/EBM/IKA-UDIP-2010
Diagnosis
• Patient with complaint
• History
• Physical
• Simple test
• Specific test: If the test (+) what is the probability that the patient has the disease?
Yes or no answer
Predictive value is the most important
The spectrum of the presentations must resemble that in practice
SS/EBM/IKA-UDIP-2010
Treatment
• Patient with certain diagnosis: best treatment?
• Is drug X more effective than Y?
• Focus on the clinical outcome, rather than its explanation (biomolecular markers, etc)
Yes or no outcome most useful
• Not in studies with “idealized” subjects Px with DM are frequently have
hypercholesterolemia, obese, hypertension, etc
SS/EBM/IKA-UDIP-2010
Prognosis
• Usually in cohort studies
• To inform about the fate of the patient
• Absolute risk is more important than relative risk
Absolute: Your risk of having second stroke in 1 year is 30%
Relative: Your risk of having second stroke in 1 year is 2 times than in non-smokers (RR = 2)
SS/EBM/IKA-UDIP-2010
Pros : “New paradigm in medicine” “Extraordinary innovations, only 2nd to Human Genome Project”
Cons : New version of an old song „Fair‟ : Nothing wrong with EBM, but:
• Be careful in searching evidence • Meta-analyses, clinical trials, and all
study results should be critically appraised
Keyword for EBM: Methodological skill to judge the validity
of study reports (Re. Andersen B: Methodo-logical errors in medical research, 1989)
SS/EBM/IKA-UDIP-2010
• Fletcher & Fletcher: CE = The application of epidemiologic principles in problems
encountered in clinical medicine • Sackett et al: CE = The basic science for clinical
medicine • Much resistance by experts • EBM: In principle – no one disagree • All major medical journals have adopted EBM • Centers for EBM all over the world
EBM & Clinical Epidemiology
SS/EBM/IKA-UDIP-2010
Previous practice:
6 yrs medical education
40-50 yrs medical practice
Problems with patients: Dx, Rx, Px
Consultants, colleagues Textbooks Handbooks
Lecture notes Clinical guidelines CME, seminars, etc
Journals
Usu. see only Results section, or even worse, Abstract
section
SS/EBM/IKA-UDIP-2010
• Trust me
• In my experience ….
• Logically
• Textbook, handbook, capita selecta
SS/EBM/IKA-UDIP-2010
The results….
“Opinion-based medicine” • Steroid inj. in prematures to prevent RDS • Routine episiotomy • Routine circumcision • Antibiotics for flu-like syndrome • Use of immunomodulators • “Skin test” before antibiotic injection • Routine chest X-ray for pre-op preparation • CT scan after minor head trauma • etc ……
SS/EBM/IKA-UDIP-2010
What is Evidence-based Medicine?
• “The conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients”
• “Pemanfaatan bukti mutakhir yang sahih dalam tata laksana pasien”
• Integration of (1) physician’s competence (2) valid evidence from studies (3) patient’s preference
SS/EBM/IKA-UDIP-2010
WHY EBM?
1 Information overload
2 Keeping current with literature
3 Our clinical performance deteriorates with time (“the slippery slope”)
4 Traditional CME does not improve clinical
performance
5 EBM encourages self directed learning process which should overcome the above shortages
SS/EBM/IKA-UDIP-2010
Our textbooks are out-of-date
• Fail to recommend Rx up to ten years after it’s been shown to be efficacious.
• Continue to recommend therapy up to ten years after it’s been shown to be useless.
SS/EBM/IKA-UDIP-2010
1. Formulate clinical problems in answerable questions
2. Search the best evidence: use internet or other on-
line database for current evidence
3. Critically appraise the evidence for
Validity (was the study valid?)
Importance (were the results clinically important?)
Applicability (could we apply to our patient?)
4. Apply the evidence to patient
5. Evaluate our performance
Steps in EBM practice
VIA
SS/EBM/IKA-UDIP-2010
Diagnosis
(Determination of disease or problem)
Treatment
(Intervention necessary to help the patient)
Prognosis
(Prediction of the outcome of the disease)
Main area
SS/EBM/IKA-UDIP-2010
• A 2-year old boy presented with 6-day high fever, conjunctival injection without secretion, skin rash> blood test shows leukocytosis, high ESR, CRP +++. He was suspected to have Kawasaki disease. The pediatrician is aware of the use of immunoglobulin to prevent coronary involvement, but uncertain about the dosage or recent developments.
SS/EBM/IKA-UDIP-2010
Medical students: (Background question)
• What is Kawasaki disease? • What is the etiology? • How it is diagnosed? • What is the treatment of choice? • Complications?
SS/EBM/IKA-UDIP-2010
House officers (Foreground question)
• In a child with KD, would immunoglobulin treatment, compared with no immunoglobulin, reduce the chance to develop coronary complication?
SS/EBM/IKA-UDIP-2010
Other examples
• In women with history of eclampsia, would administration of low-dose aspirin during pregnancy prevent eclampsia? (Prevention)
In young women with solitary thyroid nodule, can USG, compared with biopsy, differentiate between benign from malignant? (Diagnosis)
In women systemic lupus erythematosus, is history of congestive heart failure, compared with no heart failure, worsen the prognosis? (Prognosis)
SS/EBM/IKA-UDIP-2010
Four elements of good clinical question: PICO
• The Patient or Problem
• The Intervention / Index
• Comparative intervention (if relevant)
• The Outcome
SS/EBM/IKA-UDIP-2010
Four elements of a well constructed clinical question: PICO
P I C O
The main
intervention
considered
The
alternative
to compare
with the
intervention
Outcome
expected
from this
intervention?
Description
of patient
or problem
B e b r i e f a n d s p e c i f i c
SS/EBM/IKA-UDIP-2010
Do all clinical questions contain 4 elements of PICO?
• No
• The C implies in the question - PIO
– Does temulawak increase appetite in undernourished children?
• Asking prevalence – PO
– How many percent of patients with TIA who subsequently develop stroke?
SS/EBM/IKA-UDIP-2010
Relevance: Type of Evidence
• POE: Patient-oriented evidence
– mortality, morbidity, quality of life
• DOE: Disease-oriented evidence
– pathophysiology, pharmacology, etiology
SS/EBM/IKA-UDIP-2010
Comparing DOES and POEMs
Prostate
screening
PSA screening
detects prostate
Ca. early
? whether PSA
screening
mortality
DOE exists, but
POEM unknown
Antiarrhythmic
Therapy
Antihypertens.
Therapy
Drug A PVC
On ECG
Drug X BP
Drug X
mortality
Drug A >
mortality
DOE & POEM
contradicts
POEM agrees
With DOE
Example
DOE
POEM
Comment
SS/EBM/IKA-UDIP-2010
Validity: In Methods section:
– design, sample, sample size, eligibility criteria (inclusion, exclusion), sampling method, randomization method, intervention, measurements, methods of analysis, etc
Importance: In Results section
– characteristics of subjects, drop out, analysis, p value, confidence intervals, etc
Applicability: In Discussion section + our patient’s characteristics, local setting
VIA
SS/EBM/IKA-UDIP-2010
• Were the subjects randomized?
• Were all subjects received similar treatment?
• Were all relevant outcomes considered?
• Were all subjects randomized included in the analysis?
• Calculate CER, EER, RRR, ARR, and NNT
• Were study subjects similar to our patients in terms of prognostic factors?
Example: Critical appraisal for therapy
SS/EBM/IKA-UDIP-2010
Hierarchy of evidence
Meta-analysis of RCT Large RCT Small RCT Non-Randomized trials Observational studies Case series / reports Anecdotes, expert, consensus
Level 1
Level 2
Level 3
Level 4
A
B
C
Rec Weight of
Scientific
Scrutiny
For complete description see www.cebm.net
SS/EBM/IKA-UDIP-2010
Implementation of EBM practice: How to get started
1. Teaching EBM in medical schools / PPDS
Easier than to change the already existing attitude
Most important
May be included in formal curricula or integrated in
existing activities: ward rounds, on calls, case
presentations, group discussions, journal clubs, etc
2. Workshop for teaching staff
3. Workshop for practitioners, incl. nurses
SS/EBM/IKA-UDIP-2010
Resistance to EBM teaching & learning
Rudimentary skill in critical appraisal /
methodological skill
Limited resources, esp. time factor
Lack of high quality evidence
Skepticism toward evidence-based practice
‘Happy’ with current practice
SS/EBM/IKA-UDIP-2010
The
EBM
Cycle
Patient
With problem
Formulate In answerable
question
Search the
evidence
Appraise The
evidence
Apply The
evidence
SS/EBM/IKA-UDIP-2010
Criticism to EBM • EBM makes expensive medical care
• EBM cannot be implemented in developing countries
• EBM is costly and time consuming
• EBM ignore pathophysiology & reasoning
• EBM ignore experience and clinical judgment
• EB-guidelines etc interfere with professional autonomy
SS/EBM/IKA-UDIP-2010
Criticism to EBM
EBM makes expensive medical care
Cf:
–Routine antibiotics for ARTI & diarrhea
–Liberal indication for C-section
–Unnecessary sophisticated procedures / exams
–Unnecessary / harmful treatment: steroid for recurrent cough
SS/EBM/IKA-UDIP-2010
Criticism to EBM
EBM cannot be implemented in developing countries
– By definition EBM is implemented if it is implementable (patient’s preference and local condition) – for the benefit of the patients and the community
SS/EBM/IKA-UDIP-2010
Criticism to EBM
EBM is costly and time consuming
– EBM does requires facilities at the cost of quality medical care!
– Cost benefit ratio should be assessed in individual and community levels
SS/EBM/IKA-UDIP-2010
Criticism to EBM
EBM ignores pathophysiology & reasoning
– EBM encourages clinical reasoning in the light of valid and important evidence
– Pathophysiology and reasoning should be seen as hypothesis and should end-up in empirical evidence
SS/EBM/IKA-UDIP-2010
Criticism to EBM
EBM ignore experience and clinical judgment
– Personal experience and clinical judgment are by no means can be eliminated
– EBM encourage detailed and systematic documentation of experience and judgment
– Subjective experience should be, whenever possible, translated into more objective measures
SS/EBM/IKA-UDIP-2010
Criticism to EBM EB-guidelines interfere with professional autonomy
– Professional conduct (competence, altruism, openness, collegiality, ethics) is encouraged in EBM
– Every physician should develop their own practice attitude based on his/her profess-ionalism, valid evidence, and patient’s values
– Development of clinical guidelines and other standards of care should be seen as a guide and implemented according to clinical setting
SS/EBM/IKA-UDIP-2010
Advantages of EBM • Encourages reading habit • Improves methodological skill (and
willingness to do research?!) • Encourages rational & up to date
management of patients • Reduces intuition & judgment in clinical
practice, but not eliminates them • Consistent with ethical and medico-legal
aspects of patient management
SS/EBM/IKA-UDIP-2010
End result
Self directed, life-long learning attitude
for high quality patient care