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

Abstract Introduction Extended duration anticoagulation with rivaroxaban for an additional 6–12 months can reduce recurrent venous thromboembolic events (VTE) compared to placebo by ~ 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 patients who 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.