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.