Abstract
OBJECTIVES: To 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. METHODS: A 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 (3.32, reflecting relevant disease impact. CONCLUSION: SDAI-LDA is associated with more structural damage over 2 years than any of the definitions of remission. It also allows substantial disease impact to go unchecked and uncontrolled. Physicians should strive for remission whenever possible and safe while also taking into account the different individual disease activity parameters included in the adopted definition.