To describe use of the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) rheumatoid arthritis (RA) remission criteria in clinical practice.
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.
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 <3%. Remission status and examination results for each patient varied substantially among physicians, as determined by multilevel analyses.
Cross-sectional remission occurred in 5.0-10.1% of the patients in these cohorts, with cumulative remission being 2-3 times greater; however, long-term remission was rare. Problems with reliability and agreement limit the usefulness of these criteria in the individual patient. However, the criteria can be an effective method for measuring clinical status and treatment effect in groups of patients in the community.