Direct Comparison of Low-Dose Dabigatran and Rivaroxaban for Effectiveness and Safety in Patients with Non-Valvular Atrial Fibrillation

Background: We aimed to examine the comparative effectiveness and safety between low-dose dabigatran and rivaroxaban in atrial fibrillation (AF) patients. Methods: Using the National Health Insurance claims database in Taiwan, we conducted head-to-head comparisons among adult non-valvular AF patients prescribed with dabigatran 110 mg or rivaroxaban 15 mg between June 1, 2012 and May 31, 2015. A propensity score was derived using logistic regression to model the probability of receiving different non-VKA oral anticoagulants (NOACs) as a function of potential confounders, and an inverse-probability-of-treatment-weighted (IPTW) pseudo-cohort was created. A Cox proportional hazards model was used to compare clinical outcomes in the IPTW pseudo-cohort as the primary analysis. The propensity score-matched analysis was applied as the secondary analysis. Results: Overall, 13505 dabigatran 110 mg users and 6551 rivaroxaban 15 mgusers were identified. In the primary analysis, the rivaroxaban 15 mg users had a higher risk of all-cause death [hazard ratio (HR) 1.19, 95% confidence interval (CI) 1.02-1.38]. In addition, the rivaroxaban 15 mg users had an increased risk of all-cause death (HR 1.25, 95% CI 1.05-1.50) in the secondary analysis. The risks of ischemic stroke, intracranial hemorrhage and gastrointestinal hemorrhage were similar between the 2 study groups in both the primary and secondary analyses. Conclusions: For non-valvular AF patients, rivaroxaban 15 mg seemed to be associated with an increased risk of all-cause death compared with dabigatran 110 mg. This was a retrospective data analysis and the results should not be over-interpreted to guide the choice of different NOACs.