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

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; 9:2225-32.

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

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

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

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)

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?)

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

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

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.