Comparison of the Cost-effectiveness of New Oral Anticoagulants for the Prevention of Stroke and Systemic Embolism in Atrial Fibrillation in a UK Setting

Abstract

PurposeThree new oral anticoagulants (NOACs) have recently become available in the United Kingdom as an alternative to warfarin in the prevention of stroke and systemic embolism in atrial fibrillation. This study examines the relative cost-effectiveness of dabigatran (BID dosing of 150 mg or 110 mg based on patient age), rivaroxaban, and apixaban from a UK payer perspective. MethodsA previously published model that follows up patients through treatment of atrial fibrillation during a lifetime was adapted to allow comparison of the 3 NOACs and warfarin. Acute thromboembolic and bleeding events, as well as long-term consequences of stroke, intracranial hemorrhage, and acute myocardial infarction, were tracked. Relative efficacy was calculated from a formal indirect treatment comparison using data from the 3 key trials (Randomized Evaluation of Long-Term Anticoagulation Therapy, Rivaroxaban Once-daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation, and Apixaban for the Prevention of Stroke in Subjects With Atrial Fibrillation) of the NOACs. Data from the rivaroxaban trial were adjusted for the difference in international normalized ratio control among warfarin patients versus the other 2 trials. Model outputs included total costs, event rates, and quality-adjusted life-years. FindingsAmong the patients taking NOACs, those taking dabigatran had the highest total QALYs (7.68 QALYs), followed by apixaban (7.63 QALYs) and rivaroxaban (7.47 QALYs). Patients taking dabigatran had the lowest total lifetime costs (£23,342), followed by apixaban (£24,014) and rivaroxaban (£25,220). The differences between dabigatran and apixaban were modest but consistent in sensitivity analyses, with the directionality only changing at the limits of the CIs for the relative risks of ischemic stroke or intracranial hemorrhage or when assuming that both treatment discontinuation and post-event disability rates differ by drug. ImplicationsDabigatran was found to be economically dominant over rivaroxaban and apixaban in the UK setting. These economic findings are based on relative clinical efficacy from an indirect treatment comparison and would benefit from any data of direct comparisons of the NOACs in the future.