Low-Molecular-Weight Heparin Versus Unfractionated Heparin for Prophylaxis of Venous Thromboembolism in Medicine Patients—A Pharmacoeconomic Analysis

BACKGROUND: Prevention of in-hospital venous thromboembolism (VTE) is identified internationally as a priority to improve patient safety. Advocated alternatives include low-dose unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). Although LMWHs are as effective as UFH, less frequent administration and potentially safer adverse effect profile associated with LMWHs might off-set greater drug acquisition costs. The objective of this study was to determine the most cost-effective thromboprophylaxis strategy for hospitalized medicine patients and specific subgroups in Canada. METHODS: A decision-analytic model assessed costs and outcomes of LMWH compared to UFH for thromboprophylaxis in at-risk hospitalized medicine patients from an institutional perspective. The outcome of interest was the incremental cost-effectiveness ratio (ICER) for preventing deep vein thrombosis (DVT) and combined untoward events (pulmonary embolism PE, major bleed, and death). The time horizon of the model was the hospital stay. RESULTS: In the base-case analysis, LMWH thromboprophylaxis resulted in higher costs (7. 40), but 3. 6 and 1. 1 fewer DVT and untoward events per 1000 patients, respectively, with associated ICERs of 2042 and 6832. Results remained predominantly stable when alternative assumptions were evaluated in the sensitivity analysis. Low-molecular-weight heparin had the most favorable economic profile in patients with a history of DVT. In the probabilistic sensitivity analysis, in 33% of simulations LMWH was less costly and more effective, whereas the reverse was true for UFH only in 13% of simulations. CONCLUSIONS: Low-molecular-weight heparin administration is a cost-effective alternative for thromboprophylaxis strategy in Canadian hospitalized medicine patients.