Assessing Rheumatoid Arthritis Disease Activity Measures in Ethnic Minority Patients in the United States: Real-World Data From the Ethnic Minority Rheumatoid Arthritis Consortium Registry.

Objective: To identify differences in disease activity parameters that influence assessment, management, and outcomes of ethnic minority (EM) rheumatoid arthritis (RA) patients.

Methods: RA patients enrolled in the Ethnic Minority Rheumatoid Arthritis Consortium registry between 2010 and 2018 were studied. Comparisons among self-identified racial and ethnic subsets and associations with RA disease activity measures and thresholds for randomized controlled trial (RCT) inclusion criteria were estimated using univariable analytical methods.

Results: An observational cohort of 1315 RA patients of mean disease duration of 10.3 years was studied and comprised 380 (28.9%) Black, 178 (13.5%) Hispanic, and 126 (9.6%) Asian individuals. Compared with White participants, Black participants had lower socioeconomic status and, along with Hispanic participants, reported less years of education and tobacco use but greater disease activity and comorbidity. All 3 ethnic subsets had more prevalent seropositive RA with Black and Hispanic participants having less use of RA therapies compared with Asian participants who had the highest disease-modifying antirheumatic drug use. Composite disease activity measures that included a laboratory parameter found greater numbers to be in remission compared with patient-reported measures alone in the entire cohort. However, Black participants were less frequently in remission across all measures (approximately 2-fold for Disease Activity Score-28 joints with C-reactive protein vs. Disease Activity Score-28 joints with erythrocyte sedimentation rate) and more frequently met the RCT inclusion criteria.

Conclusion: In a real-world EM RA cohort, subjective disease activity measures were discordant with objective parameters. Further, in Black participants, achieving remission criteria was dependent on laboratory assay chosen but frequently met active disease threshold eligibility for RCTs. Standardization of RA disease measures in EM patients is needed to achieve parity with current thresholds of optimum RA care.