Racial and ethnic disparities in disease activity in patients with rheumatoid arthritis

Background Observational studies of patients with rheumatoid arthritis have suggested that racial and ethnic disparities exist for minority populations. We compared disease activity and clinical outcomes across racial and ethnic groups using data from a large, contemporary US registry. Methods We analyzed data from 2 time periods (2005-2007 and 2010-2012). The Clinical Disease Activity Index was examined as both a continuous measure and a dichotomous measure of disease activity states. Outcomes were compared in a series of cross-sectional and longitudinal multivariable regression models. Results For 2005-2007, significant differences of mean disease activity level (P <.001) were observed across racial and ethnic groups. Over the 5-year period, modest improvements in disease activity were observed across all groups, including whites (3.7; 95% confidence interval [CI], 3.2-4.1) compared with African Americans (4.3; 95% CI, 2.7-5.8) and Hispanics (2.7; 95% CI, 1.2-4.3). For 2010-2012, significant differences of mean disease activity level persisted (P <.046) across racial and ethnic groups, ranging from 11.6 (95% CI, 10.4-12.8) in Hispanics to 10.7 (95% CI, 9.6-11.7) in whites. Remission rates remained significantly different across racial/ethnic groups across all models for 2010-2012, ranging from 22.7 (95% CI, 19.5-25.8) in African Americans to 27.4 (95% CI, 24.9-29.8) in whites. Conclusions Despite improvements in disease activity across racial and ethnic groups over a 5-year period, disparities persist in disease activity and clinical outcomes for minority groups versus white patients.