1. Quality of Life Assessment
Rick Chappell, Ph.D.
Professor,
Department of Biostatistics and Medical Informatics
University of Wisconsin School of Medicine & Public Health
– Week 1, Lecture 1
BMI 542 – Week 8, Lecture 2

2. Outline for Quality of Life
General background
Data collection considerations
A good reference: Fairclough, Design and Analysis of Quality of Life Studies in Clinical Trials, 2nd ed. Chapman & Hall, 2010.

3. 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
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; 9:

4. 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: 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

5. Definition depends on context
Cancer vs. MI vs. hypertension
Early instruments were disease specific
Later, "general health status" instruments
POMS = Profile of Mood
SIP = Sickness Impact Profile
Difficulties with concept
No agreement on definitions
Lack of standardized measures

6. 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

7. 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)

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

9. How To Assess Quality of Life
Determine your QOL Objective
Choose an instrument
Reliable: “A measure is said to have a high reliability if it produces similar results under consistent conditions. “
Valid: “The degree to which an instrument measures what it is supposed to measure.”
Global measures, disease-specific measures, symptom checklists
Select your assessment time points and administration format
Develop an analysis plan

10. Data Collection Considerations
Mode
Self-administered
glasses, reading skills, fine-motor skills
Personal interview
training/background of interviewer
sensitivity to gender/ethnicity/age
hearing impairment

11. Off-the-Shelf Instruments (Example-Nocturnal O2 Therapy Trial)
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 (p<.01)
Ref: Ann Intern Med. 190, 93, 392-8, no authors listed.