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Chapter 8 Quality of Life Assessment

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Title: Chapter 8 Quality of Life Assessment


1
Chapter 8Quality of Life Assessment
2
News
  • ??????????????!???????????????????????????????????
    ??Lapatinib?????,??????????????????,??????????
  • ???HER-2?????,?????????,??????????,????????????

3
Targeted Clinical Trials
  • HER2 (the human epidermal growth factor receptor
    2) gene in metastatic breast cancer - Herceptin -
    requirement of screening the patients with
    over-expressed HER2 level (Slamon, 2001).
  • Estrogen receptor polymorphism - Estrogen
    Replacement Atherosclerosis trial (ERA,
    Herrington, et al, 2002) a total of 9 SNPs were
    identified and interaction between treatment of
    HRT and some of SNPs in elevation of lipid levels
    is suggested
  • Sample size determination Fijal, et al. (2000)
    and Maitournam and Simon (2005).

4
Targeted Clinical Trials and EGFR
  • Iressa (gefitnib) and Tarceva (Erlotinib) are
    targted at the EGFR pathway.
  • Efficacy is correlated to
  • race
  • number of gene copies
  • protein expression
  • EGFR mutation
  • Gappuzzo et al. (JNCI, 2005), Tsao, et al (NEJM,
    2005)

5
Ethnic Difference
IRESSA ------ Placebo
1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0
Non-Asian (n 1350)HR 0.93 (0.81, 1.08), P
.364 RR 6.5
Asian (n 342)HR 0.66 (0.48, 0.91), P
.011 RR 12.0
Patients surviving ()
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time, mo
6
From Tsao, et al (2005, NEJM)
7
From Tsao, et al (2005, NEJM)
8
Genomic Effect
  • The increasing evidence that genetic determinants
    may mediate variability among persons in the
    response to a drug implies that patient responses
    to therapeutics may vary among racial and ethnic
    groups.
  • After the intake of identical doses of a given
    agent, some ethnic groups may have clinically
    significant side effects, whereas others may have
    no therapeutic response.

9
Genomic Effect
  • Caraco (2004) points out that some of this
    diversity in rates of response can be ascribed to
    differences in the rate of drug metabolism,
    particularly by the cytochrome P-450 superfamily
    of enzymes
  • While ten isoforms of cytochrome P-450 are
    responsible for the oxidative metabolism of most
    drugs, the effect of genetic polymorphisms on
    catalytic activity is most prominent for three
    isoformsCYP2C9, CYP2C19, and CYP2D6.

10
Genomic Effect
  • Among these three, CYP2D6 has been most
    extensively studied and is involved in the
    metabolism of about 100 drugs including
    beta-blockers, antiarrhythmic, antidepressant,
    neuroleptic, and opioid agents.
  • Several studies revealed that some patients are
    classified as having poor metabolism of certain
    drugs due to lack of CYP2D6 activity.

11
Genomic Effect
  • Patients having some enzyme activity are
    classified into three subgroups those with
    normal activity (or extensive metabolism),
    those with reduced activity (intermediate
    metabolism), and those with markedly enhanced
    activity (ultrarapid metabolism).

12
Genomic Effect
  • The distribution of CYP2D6 phenotypes varies with
    race. For instance, the frequency of the
    phenotype associated with poor metabolism is 5 to
    10 percent in the Caucasian population but only 1
    percent in the Chinese and Japanese populations.

13
Example
  • Drug A is a fixed combination of two
    anti-platelet agents with indication for
    secondary prevention of thromboembolic stroke
    (200mg dipyridamole/25mg aspirin 1bid)
  • After the standard process of BSE, we decided to
    request a bridging study due to an ethnic
    difference in medical practice (much lower dose
    for one of the components in Taiwan) and higher
    headache-associated dropout rate in previous
    Philippine study

14
Example
  • Headache drop out rate Phillipino gt Caucasian
  • Local Bridging Study Result first 4 weeks
  • Group Placebo Reduced Dose
    2wk Full Dose
  • Full
    Dose 2wk 4wk
  • Headache 8.7 6.7
    16.3
  • drop out rate
  • Risk Management Change labelings instruction
    for use

15
Why Are We Interested in the Quality of Life?
  • The United States Food and Drug Administration
    has stated that efficacy with respect to overall
    survival and/or improvements in QOL might provide
    the basis for drug approval
  • Live longer feel better
  • Shaughnessy JA, Wittes RE, Burke G et al.
  • Commentary concerning demonstration of safety and
    efficacy of investigational anticancer agents in
    clinical trials. J Clin Oncol 1991 92225-32.

16
Outline for Quality of Life
  • General background
  • Data collection considerations

17
Your Quality of Life
How are you feeling this afternoon?
Mood
Happy
Miserable
18
What is Quality of Life?
  • WHO Health is not only the absence of infirmity
    and disease, but also a state of physical, mental
    and social well being
  • Multiple domains include physical, cognitive,
    emotional and social functioning, pain, sexual
    functioning, health perceptions, and symptoms
    such as nausea and fatigue
  • Fundamental principle quality of life is
    assessed by the patient

19
Quality of Life (1)
  • Definition depends on context
  • Cancer vs. MI vs. hypertension
  • Some instruments are disease specific
  • Others are "general health status" instruments
  • POMS Profile of Mood
  • SIP Sickness Impact Profile
  • Difficulties with concept
  • No agreement on definitions
  • Lack of standardized measures

20
Quality of Life (2)
  • One definition (Levine Croog)
  • Two Components
  • - Functioning
  • 1. Social (Major component)
  • - Get along with family friends sense of
    worth(????)
  • 2. Physical
  • - Perform daily life activities
  • 3. Emotional
  • - Stability and self control
  • 4. Intellectual
  • - Decision making ability
  • - Perceptions
  • 1. Life Satisfaction
  • - Sense of well being(????)
  • 2. Health Status
  • - Compared to others

21
Factors Which Influence Quality of Life
  • 1. Intervention
  • 2. Disease Process
  • 3. "Labeling" ? Need a control group
  • - Diagnosis brings on change
  • 4. Concomitant Care
  • 5. Non-related life events
  • (e.g. death in family)

22
Rationale in Clinical Trials
  • Quality of life may assess effect of intervention
  • primary response (treatment less toxic?)
  • side effects (treatment toxic?)
  • economic aspects (low risk/cost treatment but
    benefit high?)

23
How To Assess Quality of Life
  • Determine your QoL Objective
  • Choose an instrument
  • Reliable, valid, responsive, feasible
  • Global measures, disease-specific measures,
    symptom checklists
  • Select your assessment time points and
    administration format
  • Develop an analysis plan

24
Data Collection Considerations (1)
  • Mode
  • Self-administered
  • glasses, reading skills, fine-motor skills
  • Personal interview
  • training/background of interviewer
  • sensitivity to gender/ethnicity/age
  • hearing impairment

25
Data Collection Considerations (2)
  • Content
  • instrument validity, sensitivity specificity
  • sensitivity of questions
  • frame of reference for answers
  • (cognitive skills, privacy, cultural background)
  • Source(s)
  • participant, family or support network, health
    care providers

26
Off the Shelf Instruments
  • Off-the-shelf instruments
  • Designed to distinguish sickness from wellness
  • May not be sensitive to particular aspect of a
    given trial
  • May not be validated or "normed" in population
    being tested
  • May ask ridiculous questions for trial pop.
  • May take hours to complete
  • May impact negatively on compliance

27
Off-the-Shelf Instruments(Example-NOTT)
  • Design
  • Advanced Chronic Obstructive Pulmonary Disease
  • 24 vs. 12 hours of O2
  • Quality of life 10 outcome (No norms in this
    pop!)
  • Quality of Life Results ?
  • Patients were sick
  • Patients got worse
  • No treatment difference
  • BUT
  • Mortality ratio was 2/1 (plt.01)

28
More Perspectives
  • "Tailor Made" Instruments
  • Can be Quick and simple
  • Standardized but targeted to disease
  • Must be Validated for trial population
  • Select subsets of off-the-shelf instruments

29
More Perspectives
  • Home-made" Instruments
  • Often designed by a graduate student
  • Often too long
  • Often not validated or field tested on your
    patient population

30
Quality of Life Instruments
  • Can be simple and short
  • Classic examples for
  • Cancer
  • Congestive Heart Failure

31
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34
Quality of Life Analysis
  • Analytic methods likely to be based on a scoring
    system
  • Methods often rank based
  • Challenging to design/ compute sample size

35
Statistical Consideration
  • Multi-trait scaling and other construct
    examination
  • Reliability (internal consistency and test-retest
    reliability)
  • Correlation analyses with other instruments
  • Clinical validity (known group comparisons
    (sensitivity))
  • Responsiveness to change over time

36
Multi-trait Scaling (1)
  • Multi-trait scaling analysis will be employed to
    examine whether the individual items in the
    instrument can be aggregated into hypothesised
    multi-item scales
  • Evidence of item convergent validity is defined
    as correlation of 0.40 or greater between an item
    and its own scale (corrected for overlap).

37
Multi-trait Scaling (2)
  • Evidence of item discriminant validity will be
    based on a comparison of correlation of an item
    with its own scale and with other scales
  • Scaling success for any item is defined as an
    item correlated significantly higher with its own
    scale (corrected for overlap) than with another
    scale

38
Reliability
  • The internal consistency of the multi-item
    questionnaire scales will be assessed by
    Cronbachs alpha coefficient
  • A magnitude of gt0.70 is considered acceptable for
    group comparisons
  • The test-retest reliability of scales will be
    assessed using intraclass correlations between
    the second and retest assessments in the patients

39
Clinical Validity
  • Known-group comparison will be used to assess
    whether the questionnaire scores can discriminate
    between subgroups of patients of clinical status

40
Responsiveness Over Time
  • Mixed effects regression model or generalized
    estimating equations (GEE) will be used to test
    for the significance of changes in QL scores
    before and after treatment

41
Sample Size Requirements
  • The sample size is based on the recommendation of
    Tabachnik and Fidell that for multivariate
    analysis techniques to obtain reliable estimates
    the number of observations should be 10 times the
    number of variables in the model

42
EORTC QLQ-C30 (version 3) ????? (1)
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43
EORTC QLQ-C30 (version 3) ????? (2)
  • ???????(?????)
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44
EORTC QLQ-C30 (version 3) ????? (3)
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  • 12. ????????????,???,???,???
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  • ??

45
EORTC QLQ-C30 (version 3) ????? (4)
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  • ???????,???,???,???
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46
EORTC QLQ-C30 (version 3) ????? (5)
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  • ??) 
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47
FACT-P (???) (1)
48
FACT-P (???) (2)
49
FACT-P (???) (3)
50
FACT-P (???) (4)
51
FACT-P (???) (5)
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