Psychometric properties of the Rheumatoid Arthritis Disease Activity Index (RADAI) in a cohort of consecutive Dutch RA patients starting anti-TNF blocking treatment

Objectives: To examine the psychometric properties of the self-administered Dutch Rheumatoid Arthritis Disease Activity Index (RADAI) and its short form (RADAI-SF) in patients with rheumatoid arthritis (RA) starting with anti-TNF treatment. Method: Internal consistency was assessed with Cronbach’s alpha. A confirmatory factor analysis (CFA) was carried out to test the single factor structure. Construct validity was examined by correlating RADAI and RADAI-SF scores with DAS28 scores. Internal responsiveness was evaluated with the paired t-test and the standardized response mean (SRM). External... Mehr ...