To compare health-related quality of life (QOL) between patients with psoriatic arthritis (PsA) and patients with rheumatoid arthritis (RA), using the Medical Outcomes Study Short Form health survey (SF-36) and the Health Assessment Questionnaire (HAQ).
Both the SF-36 and the HAQ were administered to 107 PsA patients attending the University of Toronto Psoriatic Arthritis Clinic between January 1 and December 31, 1994, and to 43 RA patients attending a University of Toronto-affiliated RA clinic during the same period. Standardized assessments of disease activity and severity were also performed at each clinic visit. Logistic regression analysis was used to compare health-related QOL between PsA and RA.
Both patient populations experienced lower physical health compared with that of a general population sample. The RA patients demonstrated more active inflammatory disease at the time of assessment than the PsA patients. The PsA patients were younger, and more were men. Logistic regression analyses showed that patients with PsA reported higher levels of vitality than patients with RA, even after adjusting for the observed differences in clinical and demographic characteristics. PsA patients, however, reported more role limitations due to emotional problems and more bodily pain after adjusting for the difference in vitality and other covariates.
Although both patient populations experienced reduced QOL, there were some meaningful differences in how the 2 conditions affect health-related QOL. Further, it appeared that there may be unique disabilities associated with the psoriasis dimension of PsA.