Low-Molecular-Weight Heparin Versus Vitamin K Antagonists for the Treatment of Cancer-Associated Thrombosis: A Cost-Effectiveness Analysis

Abstract

Abstract Introduction Cancer-associated venous thromboembolism (VTE) is primarily treated with low-molecular weight heparin (LMWH), a strategy based on studies showing it to be superior to the vitamin K antagonist (VKA) warfarin for preventing VTE recurrence. Subsequent analyses suggest that the magnitude of this benefit might be less than previously determined. Neither patient-focused measures of utility nor the costs of each strategy have been evaluated in the current treatment era. Methods This is a cost-effectiveness analysis of VKA and LMWH for the treatment of cancer-associated thrombosis through use of a microsimulation model of outcomes for competing anticoagulation management strategies from a 2014 United States societal perspective. Results LMWH therapy added 0.27 QALYs relative to VKA treatment with an ICER of $217,007. One-way sensitivity analysis evaluating the utility of LMWH revealed that VKA was always the preferred strategy at a willingness to pay (WTP) threshold of $100,000 per QALY. Limitations include that the model incorporates a low VKA time in therapeutic range (TTR) and that the TTR in some centers may be higher thereby increasing the cost-effectiveness of the VKA strategy. Utilities for anticoagulation strategies were not derived from cancer patients, and preference is known to vary depending on how anticoagulation method is integrated with cancer treatment. Conclusions Our findings suggest that compared to LMWH, warfarin is a more cost-effective strategy to treat cancer-associated VTE. Although LMWH is associated with a modest increase in life expectancy, this increase comes at significant cost.