Remission of rheumatoid arthritis in clinical practice: Application of the American College of Rheumatology/European League Against Rheumatism 2011 remission criteria

Objective To describe use of the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) rheumatoid arthritis (RA) remission criteria in clinical practice. Methods Remission was examined using data on 1,341 patients with RA (91% men) from the US Department of Veterans Affairs RA (VARA) registry (total of 9,700 visits) and 1,153 patients with RA (25.8% men) in a community rheumatology practice (Arthritis and Rheumatology Clinics of Kansas [ARCK]) (total of 6,362 visits). Cross-sectional and cumulative probabilities were studied, and agreement between the various remission criteria was assessed. Aspects of reliability of the criteria were determined using Boolean-based definitions, as well as the Clinical Disease Activity Index (CDAI) and Simplified Disease Activity Index (SDAI) scoring methods proposed by the ACR/EULAR joint committee. Results When the 3-variable ACR/EULAR definition of remission recommended for use in community practice (swollen and tender joint counts ≤1, and visual analog scale score for patient's global assessment of disease activity ≤1) was applied, cross-sectional remission was 7.5% (95% confidence interval [95% CI] 6.4, 8.7%) for ARCK and 8.9% (95% CI 7.9, 9.9%) for VARA, and cumulative remission (remission at any observation) was 18.0% (for ARCK) and 24.4% (for VARA), over a mean followup of ∼2.2 years. Addition of the erythrocyte sedimentation rate or C-reactive protein level to the criteria set reduced remission to 5.0–6.2%, and use of the CDAI/SDAI increased the proportions to 6.9–10.1%. Moreover, 1.8–4.6% of the patients met remission criteria at ≥2 visits. Agreement between criteria definitions was good, as assessed by kappa statistics and Jaccard coefficients. Among patients in remission, the probability of a remission lasting 2 years was 6.0–14.1%. Among all patients, the probability of a remission lasting 2 years was