Background The ACR/EULAR provisional definitions of remission in rheumatoid arthritis (RA), derived from and developed for clinical trials, recommend use of 28-joint count (JC). Limited data from routine clinical practices exists on the impact of extended JC on RA remission assessment.
Objectives To study a) misclassification of ACR/EULAR RA remission when using extended JC (42-JC) versus 28-JC b) impact of non-28 joint (i.e. joints excluded from 28-JC) involvement in patients meeting 28-JC remission.
Methods 9450 (7896 with complete data) patients in the Quantitative Standard Monitoring of Patients with RA (QUEST-RA) database receiving usual care from rheumatologists in 32 countries were analyzed. ACR/EULAR remission criteria was defined by fulfillment of all of the following: tender JC ≤1, swollen JC ≤1, patient's global assessment ≤1, and Erythrocyte Sedimentation Rate (ESR) <30 mm/h for women or <20 mm/h for men. ESR was used due to its wider availability and measurement uniformity. For extended JC based remission, 42-JC was used (which additionally included bilateral hips, ankles and metatarsophalangeal joints). We compared characteristics of patients who met 28-JC based ACR/EULAR remission with and without non-28 joint involvement.
Results 739 (9.4%) patients met the 28-JC ACR/EULAR remission criteria. 663 (8.4%) patients would meet remission criteria if 42-JC was used, giving a misclassification rate of 1%. Among patients in 28-JC ACR/EULAR remission, 97 (13.1%) had ≥1 tender and/or swollen non-28 joint. Patient in remission with non-28 joint involvement were less likely to meet good functional status criteria (HAQ ≤0.5). Several patient reported outcomes and MDGL were statistically significantly worse in these patients (Table). However, the absolute magnitudes of difference were of questionable clinical relevance. There was no difference in sociodemographic, RA characteristics or treatment pattern among the two groups.
Conclusions Our data from patients in routine clinical care from several countries provides further support to the suitability of using 28-JC for assessment of RA remission.
Disclosure of Interest None declared