Grant: Operating Grant: Advancing Theoretical & Methodological Innovations in Hlth Res

Information about health-related quality of life (HRQOL), a person's perceptions of his/her well-being, is collected in many chronic disease studies. HRQOL is a broad construct that captures multiple aspects of health: physical, psychological, social, and emotional. A key question in longitudinal studies is: 'Is there significant improvement or deterioration in HRQOL over time?' This question is often difficult to answer because HRQOL data can be affected by response shift, which is defined as changes in an individual's internal standards, values, or conceptualizations of health. When response shift is present in the data, conventional statistical methods may lead to erroneous conclusions about change in HRQOL over time. Our research team will develop and compare new statistical methods to test for response shift and show how to apply them to HRQOL data for stroke patients and patients with inflammatory bowel disease. Our research will contribute to improving the quality of life of individuals with chronic health conditions by providing researchers and clinicians with methods and tools to accurately evaluate change in HRQOL and other self-report measures of health.