Evaluating Brazil’s national administrative claims data for real-world pharmacoepidemiologic studies: Trends in rheumatoid arthritis using DATASUS (2010–2020)

Objective: Our study assessed DATASUS as a potential source for pharmacoepidemiologic studies in rheumatoid arthritis (RA) in the Brazilian population focusing on treatment patterns and determinants of initiating or switching to a novel therapy. Methods Descriptive database study of RA patients with at least one claim of RA and ≥ 2 claims of disease-modifying anti-rheumatic drug (DMARD); conventional synthetic (cs), biologic (b) or targeted synthetic (ts) DMARD with more than < 6 month of follow-up from 01-Jan-to 31-Dec-2020. Analyses were stratified for SUS and non-SUS-exclusive user cohorts. Results We identified 250,251 patients with RA: mean age of 58.4 years, majority female (83%) and white (58%). 62% were SUS-exclusive and 38% non-SUS exclusive. Most common bDMARD was adalimumab and etanercept. Age (adjusted odds ratio 1.78 [50+]; 95% CI 1.57–2.01), SUS exclusive (0.53;0.47–0.59), distance to clinic [160 + km] (0.57;0.45–0.72), and pre-index csDMARD claims (1.23;1.08–1.41) were independent predictors of initiating a novel oral tsDMARD. Switching from bDMARD to tsDMARD, associations were similar, except directionality of SUS exclusive (adjusted hazard ratio 1.10;1.03–1.18), distance to clinic (1.18;1.03–1.35), and number of previous bDMARD (0.15;0.14–0.16). Conclusion DATASUS is a valid source for treatment-related analyses in RA reflecting the public health system in Brazil.