Psychometric properties of the Rheumatoid Arthritis Disease Activity Index (RADAI) in a cohort of consecutive Dutch patients with RA starting anti-tumour necrosis factor 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 starting anti-tumour necrosis factor treatment. Method: Internal consistency was assessed with Cronbach’s α. 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 Disease Activity Score in 28 joints (DAS28). Internal responsiveness was evaluated with the paired t test and the standar... Mehr ...