The differential contribution of condition-specific measures to the Behavioral Risk Factor Surveillance System (BRFSS) health-related quality of life (HRQOL) items in rheumatic disease patients

Shannon S. Currey, Ph.D., Leigh F. Callahan, Ph.D. (2001). Thurston Arthritis Research Center, UNC–Chapel Hill; Jaya K. Rao, MD, Center for Health Services Research, Durham, NC Presentation at the 2001 Society of Behavioral Medicine meeting in Seattle, WA

Generic measures of HRQOL are increasingly used for clinical and policy decision-making in chronic conditions. It is important to understand how condition-specific measures contribute to individuals' ratings on these broader measures. This study examined the contribution of four standard rheumatic condition-specific health status and psychological measures to the BRFSS HRQOL items in 653 rheumatic disease patients (160 fibromyalgia, 146 osteoarthritis, 347 rheumatoid arthritis). Self-report questionnaires included the BRFSS HRQOL items, a disability assessment (Modified Health Assessment Questionnaire), the helplessness subscale of the Rheumatology Attitudes Index, and pain and fatigue visual analog scales. The BRFSS HRQOL items assess global health and the number of days in the past 30 of poor physical or mental health, or activity limitations. Analyses were adjusted for demographic (sex, age, education) and disease factors (disease duration and number of comorbid chronic conditions). All F-statistics used 1 and 641 degrees of freedom, and reported effects are significant at p<.05. Poorer global health was associated with greater fatigue (F=13.7), disability (F=30.6), and helpessness (F=44.5). Poor physical health days were associated with greater pain (F=16.4), fatigue (F=5.5), disability (F=41.8), and helplessness (F=48.3). Limited activity days were associated with greater pain (F=4.96), disability (F=56.2), and helplessness (F=37.6). Independent of demographic and disease variables, condition-specific health status and psychological measures differentially contribute to the generic BRFSS HRQOL items.