Cost-Effectiveness Analysis of Extended Duration Anticoagulation with Rivaroxaban to Prevent Recurrent Venous Thromboembolism

Introduction: Extended duration anticoagulation with rivaroxaban for an additional 6-12 months can reduce recurrent venous thromboembolic events (VTE) compared to placebo by similar to 82%, but at the detriment of increased bleeding. We sought to estimate the cost-effectiveness of extended duration prophylaxis of recurrent VTE with rivaroxaban. Material and Methods: A Markov model was developed to estimate the cost-effectiveness of extended duration rivaroxaban, 20 mg daily, compared to placebo using a Medicare perspective, a one-month cycle length and a 40-year time horizon. The model assumed a cohort of 58-year-old patientswho had already completed an initial 6-12 months of anticoagulation with rivaroxaban or a vitamin K antagonist; and whom prescribers had clinical equipoise with respect to the need for continued anticoagulation. Data sources included EINSTEIN-Extension and other published studies of VTE. Outcomes included direct treatment costs (in 2013US$), quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). Results: Extended duration rivaroxaban resulted in higher treatment costs ($ 22,645 vs. $ 22,083) but yielded greater QALYs (16.167 vs. 16.134) as compared to placebo; corresponding to an ICER of $ 17,030/QALY gained. Our model was most sensitive to the baseline risk of bleeding and recurrent VTE, the hazard ratio of developing a recurrent event while on rivaroxaban and time horizon. Monte Carlo Simulation suggested rivaroxaban would be cost-effective in 66% of 10,000 iterations, assuming a willingness-to-pay threshold of $ 50,000/QALY. Conclusion: Despite the cost of rivaroxaban and an increased risk of bleeding, extending VTE treatment for an additional 6-12 months with rivaroxaban was found cost-effective compared to the placebo over a 40-year time horizon. (C) 2014 Elsevier Ltd. All rights reserved.