Drug Utilization Pattern of Oral Anticoagulants in Patients with Atrial Fibrillation: A Nationwide Population-Based Study in Korea.

Anticoagulants are drugs that thin blood with the purpose of preventing thromboembolic disease (e.g., stroke), which is a disease occurring when a blood clot forms or blocks vessel. Maintaining treatment for anticoagulation is important to prevent stroke in atrial fibrillation (AF) patients. To understand current drug usage pattern and treatment changes related to oral anticoagulants (OAC) we examined OAC treatment patterns and preceding events that led to drug switch or stop and medication maintenance by Korean AF patients.The study was conducted by utilizing the Korean national claims data from July 2015 to November 2016. All AF patients who newly started taking OAC were included in the analysis. In total, 48,389 patients were identified with most (83%) taking nonvitamin K antagonist oral anticoagulants (NOAC), which are newer generation blood thinners, including apixaban, dabigatran, and rivaroxaban, and 18% taking warfarin, the conventional blood thinner. Compared to warfarin, NOAC users were less likely to switch to other treatment. NOAC users discontinued the treatment less frequently than warfarin users. Thromboembolic events commonly preceded switch between OACs. Patients who stopped taking OACs were often confronted with a bleeding event before stopping treatment. Apixaban takers showed higher treatment persistence compared to dabigatran or warfarin users. In this study, we determined that treatment change is common in OAC-using patients. The results suggest that NOAC users may better adhere to treatment than warfarin users.