Validation of ACR/EULAR definition of remission in rheumatoid arthritis from RA practice: the ESPOIR cohort

Using data from those who met RA criteria in the ESPOIR cohort, we matched each person in remission with a person not in remission and then carried out analyses comparing later stability of x-ray and health assessment questionnaire (HAQ) between the two groups. We compared the predictive validity of the same candidate definitions of remission evaluated in the ACR/EULAR process. To minimize potential bias and produce more stable results, we used a bootstrap resampling approach to select those not in remission, repeating the sample matching analysis process 500 times.Results were similar to those of clinical trials analyzed for the ACR/EULAR remission criteria. Specifically, the ACR/EULAR remission definitions using either an simple disease activity index (SDAI) ≤ 3.3, clinical disease activity index (CDAI) ≤ 2.8 or a definition of remission requiring tender joint count, swollen joint count, patient global assessment all ≤ 1 performed as well or better than other candidate definitions of remission in terms of predicting later x-ray and function stability.ACR/EULAR definitions of remission developed for trials are similarly valid in observational studies in RA and could be used in practice.Recently a committee consisting of members of the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) with help from Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) produced a new rheumatoid arthritis (RA) remission definition for use in clinical trials [1]. While the committee developed a remission definition using only trial data, suggestions were made for remission definitions to be used in practice. The performance of the trial-based definitions in practice-based settings and of those proposed for use in practice has not been fully examined. If these new RA remission definitions perform as comparably in observational studies as in randomized clinical trials, then these might also be used as practice-based criteria.While stu