Wells Philip S, Lensing Anthonie W A, Haskell Lloyd, Levitan Bennett, Laliberté François, Durkin Michael, Ashton Veronica, Xiao Yongling, Crivera Concetta, Lejeune Dominique, Schein Jeff, Lefebvre Patrick
a Department of Medicine , University of Ottawa, Ottawa Hospital Research Institute , Ottawa , ON , Canada.
b Bayer Pharma AG , Wuppertal , Germany.
J Med Econ. 2018 Jun;21(6):587-594. doi: 10.1080/13696998.2018.1444615. Epub 2018 Mar 16.
The EINSTEIN-Extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (vs placebo) after 6-12 months of initial anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small non-significant increased risk of major bleeding (none fatal or in critical site). This study aimed to compare total healthcare cost between rivaroxaban and placebo, based on the EINSTEIN-EXT event rates.
Total healthcare cost was calculated as the sum of treatment and clinical event costs from a US managed care perspective. Treatment duration and event rates were obtained from the EINSTEIN-EXT study. Adjustment on treatment duration was made by assuming a 10% non-adherence rate. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e. recurrent deep vein thrombosis [DVT], recurrent pulmonary embolism, major bleeding, clinically relevant non-major bleeding) were determined from the literature. Results were examined over a ±20% range of each cost component and over 95% confidence intervals (CIs) of event rate differences in deterministic (one-way) and probabilistic sensitivity analyses (PSA).
Total healthcare cost was $1,454 lower for rivaroxaban-treated (vs placebo-treated) patients in the base-case, with a lower clinical event cost fully offsetting drug cost. The cost savings of recurrent DVT alone (-$3,102) was greater than drug cost ($2,723). Total healthcare cost remained lower for rivaroxaban in the majority (73%) of PSA (cost difference [95% CI] = -$1,454 [-$2,396, $1,231]).
This study was conducted over the 1-year observation period of the EINSTEIN-EXT trial, which limited "real-world" applicability and examination of long-term economic impact. Assumptions on drug and clinical event costs were US-based and, thus, not applicable to other healthcare systems.
Total healthcare costs were estimated to be lower for patients continuing rivaroxaban therapy compared to those receiving placebo in VTE patients who had completed 6-12 months of VTE treatment.
“爱因斯坦-拓展”试验（EINSTEIN-EXT）发现，在初始抗凝治疗6至12个月后，继续使用利伐沙班额外治疗6个月或12个月（与安慰剂相比）可显著降低复发性静脉血栓栓塞（VTE）的风险，同时大出血风险有小幅增加但未达显著水平（均非致命性或发生在关键部位）。本研究旨在根据EINSTEIN-EXT的事件发生率，比较利伐沙班和安慰剂的总医疗费用。
从美国管理式医疗的角度，将总医疗费用计算为治疗费用和临床事件费用之和。治疗持续时间和事件发生率取自EINSTEIN-EXT研究。通过假设10%的不依从率对治疗持续时间进行调整。药品成本基于批发采购成本。临床事件（即复发性深静脉血栓形成[DVT]、复发性肺栓塞、大出血、临床相关非大出血）的成本估计来自文献。在确定性（单向）和概率敏感性分析（PSA）中，对每个成本组成部分的±20%范围以及事件发生率差异的95%置信区间（CI）进行结果检验。
在基础病例中，接受利伐沙班治疗的患者（与接受安慰剂治疗的患者相比）总医疗费用低1454美元，较低的临床事件成本完全抵消了药品成本。仅复发性DVT节省的成本（-3102美元）就大于药品成本（2723美元）。在大多数（73%）的PSA中，利伐沙班的总医疗费用仍然较低（成本差异[95%CI]=-1454[-2396,1231]美元）。
本研究是在EINSTEIN-EXT试验的1年观察期内进行的，这限制了“真实世界”的适用性以及对长期经济影响进行考察。药品和临床事件成本的假设基于美国，因此不适用于其他医疗体系。
对于已完成6至12个月VTE治疗的VTE患者，继续接受利伐沙班治疗的患者估计总医疗费用低于接受安慰剂治疗的患者。
