Translating Treatment Effects Between Rheumatoid Arthritis Activity Measures and American College of Rheumatology Responses in Direct Comparison Trials

Direct comparison trials in rheumatoid arthritis (RA) increasingly use changes in continuous disease activity measures as endpoints. However, the between-arm differences in these scores that are clinically meaningful are uncertain. To aid interpretation of clinical trials that use the Disease Activity Score in 28 joints (DAS28) or Simplified Disease Activity Index (SDAI) as endpoints, we developed statistical equivalences between changes in...