Disparities in burden of disease in patients with rheumatoid arthritis across racial and ethnic groups.

To examine racial/ethnic differences in rheumatoid arthritis (RA) disease burden and change in clinical outcomes over time. We included CorEvitas Rheumatoid Arthritis Registry patients from two time periods (2013-2015 and 2018-2020). Clinical Disease Activity Index (CDAI) (as a continuous measure and as a dichotomous measure) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) were assessed at each visit. Marginal means and their corresponding 95% confidence interval (CI) by race/ethnicity were estimated for each outcome using adjusted mixed effects linear and logistic regression models. Overall and pairwise tests were conducted to detect differences between race/ethnicity groups. Of 9,363 eligible patients (8,142 White, 527 Black, 545 Hispanic, 149 Asian), most (76%-85%) were female. At Visit 1, the mean disease duration ranged from 9.8-11.8 years. Estimated CDAI was significantly higher for Hispanics compared to Whites at Visit 1 (11.1 vs. 9.9; pairwise P = 0.033) and Visit 2 (9.2 vs. 8.0, pairwise P = 0.005). Disease activity improved over the 5-year study period among all race/ethnicity groups, though Hispanics improved less than Whites. Disease activity improved over the 5-year period across all racial/ethnicity groups, and disparities between racial/ethnicity groups in disease activity and functional status did persist over time, suggesting that further effort is needed to understand the drivers of these discrepancies to close this race/ethnicity gap. Key Points • Disease activity improved over the 5-year period across all racial and ethnic groups. • Disparities between racial and ethnic groups in disease activity and functional status did persist over time, suggesting that further effort is needed to understand the drivers of these discrepancies and close this racial gap.