Remission versus low disease activity as treatment targets in rheumatoid arthritis: how to strike the right balance between too strict and too lenient targets? A meta-epidemiological study of individual patient data

ObjectivesTo evaluate the impact of using Simplified Disease Activity Index (SDAI)-LDA (low disease activity) versus different definitions of remission as a treatment target in established rheumatoid arthritis.MethodsA meta-epidemiological study of individual patient data from eight randomised controlled trials was performed. Four definitions of the target were considered at 6 months: (1) SDAI-LDA: SDAI≤11; (2) SDAI-Remission: SDAI≤3.3; (3) 4V-Remission: Tender and swollen 28-joint counts and C reactive protein (mg/dL) all ≤1 and patient global assessment (PGA)≤2 and (4) 3-variable (3V)-Remission: as 4V, excluding PGA. The mean radiographic change in the modified total Sharp-van der Heijde score (mTSS) and the Good Radiographic Outcome rates (defined as a change of ≤0.5 units mTSS) over 2 years were compared among target definitions. Radiographic progression and the distribution of the individual criteria of the Boolean definition in the only LDA subgroup (3.3