Real-World Comparative Effectiveness and Cost Comparison of Thromboprophylactic Use of Enoxaparin versus Unfractionated Heparin in 376,858 Medically Ill Hospitalized US Patients

BACKGROUND: Venous thromboembolism (VTE) is a serious complication in medically ill inpatients. Enoxaparin or unfractionated heparin (UFH) thromboprophylaxis has been shown to reduce VTE in clinical trials; however, comparative effectiveness and differences in hospital costs are unknown in US hospital practice. OBJECTIVE: This study compared clinical and economic outcomes between enoxaparin and UFH thromboprophylaxis in medically ill inpatients. METHODS: A retrospective cohort study was conducted using the Premier Healthcare Database between 1 January 2010 and 30 September 2016. Inpatients aged ≥ 18 years with a ≥ 6-day hospital stay for serious medical conditions were included. Two patient groups receiving thromboprophylaxis were identified during hospitalization: one receiving enoxaparin and other receiving UFH. Regression models were constructed to compare VTE events, in-hospital mortality, pulmonary embolism (PE)-related mortality, major bleeding, and total hospital costs during both the index hospitalization and the 90-day readmission period between the two groups. RESULTS: A total of 242,474 and 134,384 inpatients received enoxaparin or UFH for thromboprophylaxis, respectively. Compared with UFH prophylaxis, enoxaparin was significantly associated with 15%, 9%, 33%, and 41% reduced odds of VTE, in-hospital mortality, PE-related mortality, and major bleeding, respectively, during index hospitalization, and 10% and 19% reduced odds of VTE and bleeding, respectively, during the readmission period. Mean total hospital costs were significantly lower in patients receiving enoxaparin prophylaxis than in those given UFH. CONCLUSIONS: Thromboprophylaxis with enoxaparin was associated with significantly reduced in-hospital VTE events, death, and major bleeding and lower hospital costs compared with UFH in hospitalized medically ill patients.