Objectives: To evaluate treatment response, healthcare resource utilization, and direct costs for patients with rheumatoid arthritis (RA) initiating conventional disease-modifying antirheumatic drugs (csDMARDs) or biologics in Taiwan.

Methods: A retrospective observational study using Taiwan’s National Health Insurance Research Database from 1/1/2015 to 12/31/2018 was conducted. Two mutually exclusive RA cohorts, incident csDMARDs users and incident biologic users, were identified and enrolled upon their first claim for a csDMARD or a biologic, in 2016, respectively. Response (stable or inadequate response [IR]) to csDMARDs and biologics was measured using a validated claims-based algorithm in the one-year after initiation. Healthcare resource utilization and direct costs (NT$) were for up to two years post enrollment.

Results: There were 7,570 and 1,770 RA patients newly initiating a csDMARD or biologic in 2016, respectively. After one-year, 28.4% and 70.1% of csDMARD initiators and 55.4% and 42.9% of biologic initiators were classified as stable or IR, respectively. RA-related hospital admissions, hospital days, emergency department visits, and outpatient visits were all significantly (p<0.01) higher for patients with IR compared to stable response in csDMARD initiators. Biologic initiators with IR had significantly higher (p<0.001) RA-related hospital admission and hospital days compared to stable response. Patients with a stable response had lower mean total direct costs than IR in both the csDMARD (NT$54,276 vs. NT$63,163; p=0.0346) and biologic cohorts (NT$392,279 vs. NT$409,408; p=0.0174). Total direct costs rose an average of 25.8% (driven by a 79.6% increase in medication costs) from year one to year two for csDMARD IR patients, compared to a 0.9% increase for stable patients.

Conclusions: RA patients initiating their first csDMARD or biologic and achieving a stable response demonstrated lower healthcare resource utilization and costs, compared to those with an inadequate response.