Real-world treatment patterns of rheumatoid arthritis in Brazil: analysis of DATASUS national administrative claims data for pharmacoepidemiology studies (2010-2020)

Abstract

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. This was a 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 months of follow-up from 01-Jan-2010 to 31-Dec-2020. Analyses were stratified for SUS-exclusive and SUS+ private user cohorts. We identified 250,251 patients with RA in DATASUS: mean age of 58.4 years, majority female (83%) and white (58%). 62% were SUS-exclusive and 38% SUS+ private. Most common bDMARDs were adalimumab and etanercept. Age (adjusted odds ratio 1.78 [50+]; 95% CI 1.57-2.01), SUS exclusive status (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 for the direction of associations for SUS exclusive status (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). DATASUS is a source suitable for treatment-related analyses in RA reflecting the public health system in Brazil.

Figure 1

Study population of b/tsDMARD-treated rheumatoid arthritis patients in DATASUS with cohorts defined by their dependency on Brazil´s public health system (Sistema Único de Saúde), either exclusively (SUS_exclusive) or in combination with private insurance coverage (SUS+ private) (STROBE diagram). RA rheumatoid arthritis, DMARD disease modifying antirheumatic drug, N total number of patients, SUS Sistema Único de Saúde, SUS-exclusive comprehensive public health system for the entire population, SUS+ private refers to individuals on SUS only for prescription drug coverage.

Figure 2

Prevalent users (a) and new users (b) of b/tsDMARD treatment among patients with rheumatoid arthritis in DATASUS per year. Prevalent users: patients with RA currently receiving b/tsDMARD treatment, percentage shown by b/tsDMARD type by year. New users: patients with RA initiating a new b/tsDMARD treatment (i.e., their first prescription). b/tsDMARD biologic/targeted synthetic DMARD. tsDMARD limited to tofacitinib at time of analysis.

Figure 3

Previous use of csDMARD before initiating b/tsDMARD, stratified by SUS coverage dependency (exclusive or with private insurance) among patients with rheumatoid arthritis in DATASUS. b/tsDMARD biologics target synthetic disease modifying antirheumatic drug. tsDMARD limited to tofacitinib at time of analysis. SUS-exclusive, dependent on SUS for all healthcare resources; SUS+ private, individuals dependent on SUS only for prescription drug coverage. csDMARD conventional synthetic disease modifying antirheumatic.

Figure 4

(a) Sankey diagram depicting treatment sequencing among patients with rheumatoid arthritis initiating a b/tsDMARD who transition to a second-line, and/or third-line treatment (N = 31,232). b/tsDMARD biologic target synthetic disease modifying antirheumatic drug; tsDMARD limited to tofacitiniv at time of analysis; Sankey diagram limited to b/tsDMARDs. csDMARDs, conventional disease modifying antirheumatics, not shown and may be combination with b/tsDMARDs). (b) Sankey diagram of patients with rheumatoid arthritics initiating a b/tsDMARD who transition to a second-line, or third-line treatment (SUS-exclusive cohort) in DATASUS (N = 18,042). b/tsDMARD biologic target synthetic disease modifying antirheumatic. tsDMARD limited to tofacitinib at time of analysis;Sankey limited to b/tsDMARDs (csDMARD, conventional disease modifying antirheumatics, not shown and may be combination with b/tsDMARDs); SUS-exclusive are individuals, dependent on SUS for all healthcare resources. (c) Sankey diagram of patients with rheumatoid arthritis initiating a b/tsDMARD who transition to a second-line and/or third-line treatment (SUS+ private insurance cohort)in DATASUS (N = 13,190). b/tsDMARD biologic target synthetic disease modifying antirheumatic. tsDMARD limited to tofacitinib at time of analysis. Sankey limited to b/tsDMARDs (csDMARDs, conventional disease modifying antirheumatics, not shown and may be combination with b/tsDMARDs). SUS+ private insurance are individuals dependent on SUS only for prescription drug coverage.

Figure 5

Kaplan Meier plot depicting timing of switch from first-line (LOT1) to second-line treatment (LOT2) among rheumatoid arthritis patients receiving b/tsDMARD therapies in DATASUS (2010–2020). b/tsDMARD biologic target synthetic disease modifying antirheumatic; tsDMARD limited to tofacitinib at the time of analysis.