Title: Chapter 8 Quality of Life Assessment
1Chapter 8Quality of Life Assessment
2News
- ??????????????!???????????????????????????????????
??Lapatinib?????,??????????????????,?????????? - ???HER-2?????,?????????,??????????,????????????
3Targeted 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).
4Targeted 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)
5Ethnic 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
6From Tsao, et al (2005, NEJM)
7From Tsao, et al (2005, NEJM)
8Genomic 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.
9Genomic 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.
10Genomic 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.
11Genomic 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).
12Genomic 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.
13Example
- 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
14Example
- 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
15Why 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.
16Outline for Quality of Life
- General background
- Data collection considerations
17Your Quality of Life
How are you feeling this afternoon?
Mood
Happy
Miserable
18What 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
19Quality 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
20Quality 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
21Factors 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)
22Rationale 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?)
23How 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
24Data 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
25Data 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
26Off 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
27Off-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
29More Perspectives
- Home-made" Instruments
- Often designed by a graduate student
- Often too long
- Often not validated or field tested on your
patient population
30Quality of Life Instruments
- Can be simple and short
- Classic examples for
- Cancer
- Congestive Heart Failure
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34Quality of Life Analysis
- Analytic methods likely to be based on a scoring
system - Methods often rank based
- Challenging to design/ compute sample size
35Statistical 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
36Multi-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).
37Multi-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
38Reliability
- 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
39Clinical Validity
- Known-group comparison will be used to assess
whether the questionnaire scores can discriminate
between subgroups of patients of clinical status
40Responsiveness 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
41Sample 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
42EORTC QLQ-C30 (version 3) ????? (1)
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43EORTC QLQ-C30 (version 3) ????? (2)
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45EORTC QLQ-C30 (version 3) ????? (4)
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47FACT-P (???) (1)
48FACT-P (???) (2)
49FACT-P (???) (3)
50FACT-P (???) (4)
51FACT-P (???) (5)