Background: Generic health status measures are commonly used in the evaluation of rheumatoid arthritis (RA) patients. The reliability, validity, and sensitivity of the instruments in the assessment of quality of life (QOL) in RA, and how they correlate to other clinical measurements, have longbeen questioned.
Objective: Analyze the performance of a commonly used generic health status measure, the Medical Outcomes Study 36-Item Short Form (SF-36), against the Outcome Measures in Rheumatology(OMERACT) criteria.
Methods: Data were analyzed from 7 double-blind, randomized controlled trials that examined the effectiveness of 1 or more interventions in RA. The primary outcome measures evaluated were the Mental and Physical Component Scores of the SF-36. Comparators were 1 or more of the following: the Health Assessment Questionnaire scores, tender joint count (TJC), the Disease Activity Score, and the American College of Rheumatology Responder Index (ACR20,ACR50, ACR70). The ability to detect a treatment effect in the study outcomes was evaluated using 3 measures: treatment difference,standardized response mean, and relative efficiency in relation to the TJC.
Results: As a generic QOL measure, the SF-36 is better suited to capture the holistic health of the patient, as reflected in the World Health Organization definition of health as being not only the avoidance of disease but the physical,emotional, and social well-being of the patient. Furthermore, use of the SF-36 permits comparisons of physical and mental aspects of QOL in the RA patient population, as well as comparisons of QOL parameters between patients with RA, other patient groups, and the general population.
Conclusion: The SF-36 deserves serious consideration for inclusion in the core set of outcomes in RA trials.