US cost–effectiveness analysis of apixaban compared with warfarin, dabigatran and rivaroxaban for nonvalvular atrial fibrillation, focusing on equal value of life years and health years in total

Abstract

Aim: Warfarin and direct-acting oral anticoagulants (DOACs) are widely prescribed to patients with nonvalvular atrial fibrillation (NVAF) to reduce risk of stroke and systemic embolism (SE). This study aimed to assess the cost–effectiveness of apixaban compared with warfarin, dabigatran and rivaroxaban, for patients with NVAF from a US healthcare payer (Medicare) perspective. Methods: A cohort-level Markov model was developed based on a previously published model, for the US setting, factoring in anticipated price decreases due to market entry of generic drugs. Two retrospective cohort studies in US Medicare patients provided inputs to quantify clinical events in the base case setting and in a scenario analysis. For this study, equal value of life-years (evLYs) and health years in total (HYT) were used. Cost–effectiveness was assessed based on a willingness-to-pay threshold of $100,000 per evLY gained (evLYG) or HYT gained (HYTG). Results: Apixaban treatment was associated with gains of 2.23, 1.08 and 1.72 evLYs and 2.26, 1.08 and 1.73 HYTs, comparedwith warfarin, dabigatran and rivaroxaban, respectively. In the base case analysis from a Medicare perspective, apixaban was cost-effective (i.e., value for money) compared with warfarin, dabigatran and rivaroxaban, with corresponding incremental cost–effectiveness ratio (ICER) per evLYG (and HYTG) of $10,501 ($10,350), $7809 ($7769) and $758 ($768), respectively. When a societal perspective was included, and in a scenario analysis using US Medicare data from the Ray et al. study to quantify treatment effects, apixaban dominated rivaroxaban (i.e., less expensive and more effective) in terms of ICER per evLYG (and HYTG). Conclusion: Using dynamic pricing assumptions, treatment with apixaban compared with warfarin, dabigatran and rivaroxaban was associated with incremental evLYs and HYT and represents a cost-effective treatment option in patients with NVAF, from a US healthcare payer (Medicare) perspective.

Keywords

• apixaban
• cost–effectiveness
• equal value of life years
• health years in total
• medicare
• nonvalvular atrial fibrillation