1

HEALTH RELATED QUALITY OF LIFE

Fowad Khurshid

PHCL 431

2

QUALITY OF LIFE

“Quality of life” concept emerged in US after World War II Attempted to describe the effect of the acquisition

of material goods on people’s lives

Concept of health also reassessed after World War II by WHO Rather than being defined as the absence of

disease, it incorporated the perception of complete physical, mental, and social well-being

3

FACTORS AFFECTING QUALITY OF LIFE

4

DEFINITIONS OF QUALITY OF LIFE Quality of life is the degree of need and satisfaction within the physical,

psychological, social, activity, material and structural area (Hörnquist, 1982).

Quality of life is the subjective evaluation of good and satisfactory character of life as a whole (De Haes, 1988).

Health related quality of life is the subjective experiences or preferences expressed by an individual, or members of a particular group of persons, in relation to specified aspects of health status that are meaningful, in definable ways, for that individual or group (Till, 1992).

Quality of life is a state of well-being which is a composite of two components: 1) the ability to perform everyday activities which reflects physical psychological, and social well-being and 2) patient satisfaction with levels of functioning and the control of disease and/or treatment related symptoms (Gotay et al., 1992).

An individual’s perception of their position in life in the context of the culture and values systems in which they live and in relation to their goals, expectations, standards and concerns (WHO Quality of life Groups, 1993).

5

NO CLEAR DEFINITION BECAUSE

Many possible definitions

Multi-dimensionally

Subjective

Related to society

6

NO CLEAR DEFINITION BECAUSE

Different origins of research:

Clinical decision making: Does the patient benefit from the treatment?

Epidemiology (public health): what is the morbidity of the population?

Health economics: Is it worth the money?

7

QUALITY OF LIFE

Core Domains• Psychological

• Social

• Occupational

• Physical

Typical items• Depression/Anxiety/

Adjustment to illness

• Personal relationships, sexual interest, social & leisure activities

• Employment, cope household

• Pain/mobility/sleep/sexual functioning

8

HOW TO MEASURE QUALITY OF LIFE FORM A CLINICAL POINT OF VIEW?

Choose items Are you able to walk one kilometer ? Do you feel depressed ?

Choose response mode Binary yes / no Multiple (Likert) yes / at bid / hardly /

no Continuous (Visual Analogue Scale) Always

————X—— Never Combine items to dimensions of quality of life

Sum up the items belonging to one dimension Rescale sum on a scale from 0 to 100

9

HEALTH-RELATED QUALITY OF LIFE (HRQL)

Assessment includes the effect of health on well-being using environmental and economic features of the study population

Outcome measures may include patient-reported levels of pain, emotional and psychological status as well as levels of functioning

10

HEALTH-RELATED QUALITY OF LIFE (HRQL)

HRQL is a concept that reflects an individual’s perception of how an illness and its treatment affect life.

HRQL instruments are necessary to quantify the burden of a disease and functional impairment in survivors

Generic or disease specific

11

ATTRIBUTES OF HRQOL

Disease, disorder

Impairment

Disability

Handicap

12

EXAMPLES OF IMPAIRMENTS, DISABILITIES AND HANDICAPS

Impairments Pain Fatigue Anxiety Depression Incontinence

Disabilities Bathing Dressing Climbing stairs Ability to work Partnership problems

Handicaps Physical

independence Mobility Social integration Orientation Economic self-

sufficiency

13

INSTRUMENTS FOR ASSESSING QOL

Generic instruments

These instruments can be used with any population. They

generally cover perceptions on overall health and also questions

on social, emotional and physical functioning, pain and self-care.

Can be universally applied

With limitations, allow comparisons of different diseases or

populations

Do not allow disease-specific aspects to be studied

Specific instruments

This type of instrument evaluates a series of health dimensions

specific to a disease.

Specific disease instruments are more comprehensive

14

GENERIC VERSUS DISEASE-SPECIFIC INSTRUMENTS

Type Advantages Disadvantages

Generic or general

Broadly applicable May not be responsive to changes in health

Summarizes range of concepts

May not be relevant for specific populations

May detect unanticipated effects

Results may be difficult to interpret

Disease specific More relevant for specific populations

Cannot compare across populations

More responsive to changes in health

Cannot detect unanticipated effects

15

EXAMPLES OF GENERAL HRQOL MEASURES

General Health Status Instruments

Medical Outcome Study Short-Form Health Surveys (MOS-SF)4,5,6,7 (includes SF-12, SF-36, and SF-36 Version 2)

EuroQol-5D (EQ-5D)11

Quality of Well-Being (QWB) Scale12

Sickness Impact Profile (SIP)14

Dartmouth COOP15

16

EXAMPLES OF DISEASE-SPECIFIC HRQOL MEASURES

Hypertension

Health Status Index (HSI)16

The Subjective Symptom Assessment Profile17

Benign Prostatic Hyperplasia

American Urological Association Symptom Index (AUASI)18

BPH Impact Index19

Asthma and Allergy

Living with Asthma Questionnaire20

Life Activities Questionnaire for Adult Asthma21

Diabetes Mellitus

Diabetes-Specific QoL Instrument (DQOL)22

17

GENERIC INSTRUMENTS FOR ASSESSING QOL

QoL Questionnaires Administered by

Short-Form 36 (SF-36) Self

Sickness Impact Profile Observer

Beck Depression Inventory Observer

Hamilton Depression Rating Scale

Observer

Center for Epidemiological Studies of Depression

Observer

Hamilton Anxiety Scale Observer

Fatigue Severity Scale Self

18

SF-36

Brief, comprehensive self report questionnaire- 36 items 8 subscales (health concepts)

8 dimensions of health

Physical functioning (10 items)

Role limitation due to physical problems (4 items)

Pain (2 items)

General health perception (6 items)

Energy / vitality (4 items)

Social functioning (2 items)

Role limitation due to emotional problems (3 items)

Mental health (5 items)

19

APPROACHES TO CROSS-CULTURAL INSTRUMENT DEVELOPMENT

Sequential approach (transfering an existing questionnaire to another culture, e.g. SF-36 Health Survey)

Parallel approach (assembling an instrument based on existing scales from different cultures, e.g. EORTC QLQC30)

Simultaneous approach (cooperative cross-cultural development of a questionnaire, e.g. WHO-QOL)

20

STEPS IN INSTRUMENT DEVELOPMENT

Item development (focus groups; expert pannel; cognitive

debriefing)...

Translation (foreward, backward, piloting)

Psychometric testing (reliability, validity, responsiveness)

Norming (representative population sample, weighing)

21

ASSESSMENT OF QOL INSTRUMENTS (I)

Validity: ability to distinguish QoL of patients with different levels of health status

Interpretability: measurement expresses small, moderate, serious change or improvement in QoL

22

ASSESSMENT OF QOL INSTRUMENTS (II)

Reliability / reproducibility: same results for repeated measurement

Sensitivity / Responsiveness: ability to detect small but clinically significant changes in QoL

23

VALIDATION PHASES

Outlook (qualitative)

face validity – language– outlook, letter size – simplicity content validity

Content (quantitative)

criteria validity construct validity – convergence– divergence

reliability – internal consistency – reproducibility

24

LOCAL ADAPTATION OF QOL INSTRUMENTS

Validity of different language versions has to be equal with the validity of the original version

Mirror translation is not recommended

25

HOW ARE QOL MEASURES USED IN THE HEALTHCARE SETTING?

Useful to incorporate into:

Cost-effective analyses Health policy people use QoL to add the “human” impact into

cost-effective analyses

Clinical Trials How do interventions and outcomes alter QoL?

Everyday clinical practice QoL potentially a major factor for both doctor and patient

considering whether to try specific therapies (ie chemotherapy in advanced cancers)

Epidemiological studies

26

QUALITY OF LIFE ASSESSMENT CAN:-

Provide data to assist patient and doctor with decision

making about treatments

Help evaluate outcome of different treatments in

outcome trials

Identify patients who might benefit from supportive

interventions

To be used to inform policy and resource allocation

Reveal benefits to patients despite objective toxicity

be of prognostic value in determining which patient is

most likely to benefit from treatment

27

USE OF QOL

Indicator of psychological distress

Aide referral

Prognostic value - predictive of treatment

outcomes

Decision making tool

28

CHOOSING A TEST TO MEASURE QUALITY OF LIFE

Generic or specific test

Index or profile

Single instrument or battery?

Is it suitable for target population

Is it psychometrically sound?

Which response format is used?

What is the time frame?

Method of administration

Who will complete assessment?

29

METHODS OF ADMINISTRATION

Face to face interview by trained interviewers

telephone interviews

self-report questionnaires

pencil and paper

computer - touch screens and so on

30

WHY DOCTORS DO NOT MEASURE QUALITY OF LIFE

They feel that clinical judgement is sufficient

Do not know which tests to use

Feel it takes too much time

Think that the patient will get upset

Do not know how to analyse tests

Do not know how to interpret data

31

THANK YOU