A CROSS-SECTIONAL ASSESSMENT OF HEALTH-STATUS INSTRUMENTS IN PATIENTSWITH RHEUMATOID-ARTHRITIS PARTICIPATING IN A CLINICAL-TRIAL

Objective. To (I) validate die Short-Form Health Sun ey (SF-36) as a g eneric functional health status measure in patients with rheumatoid ar thritis CRA), and (2) assess correlations between the SF-36 and other outcome measures used in tile Minocycline in Rheumatoid Arthritis (MIR A) Trial. Methods, We conducted a cross sectional analysis of the fina l visit outcome measures from the 48 week, multicenter; placebo contro lled double blind MIRA trial. Multitrait scaling analyses assessed con vergent and discriminant validity and internal consistency reliability of the SF-36 in the study patients. Responses to comparable items on the SF-36 and modified Health Assessment Questionnaire (M-HAQ) regardi ng physical functioning were compared and questions from both instrume nts were also compared to other RA outcome measures, Results. In patie nts with RA, the SF-36 had high internal consistency and reliability, high discriminant and high convergent validity. Moderate correlations were observed (r = -0.46 to -0.61, p < 0.01 in each case) for comparab le items on the SF-36 and M-HAQ regarding dressing, walking, and bendi ng, Joint tenderness score correlations with items on the M-HAQ and SF -36, and joint tenderness score correlations with the SF-36 scales wer e higher than for joint swelling scores. Physician and patient global assessments were mast highly correlated (r = 0.58 and 0.66, p < 0.01, respectively) with the SF-36 bodily pain item. Conclusion. The SF-36 i s a valid Instrument for this RA population. The SF-36 correlates with the M-HAQ and the physician and patient global assessments, The usefu lness of tile SF-36 in measuring change in RA clinical trials requires testing in longitudinal studies.