INTRODUCTION AND OBJECTIVES: The purpose of this study was to determine whether some foot/ankle surgeries would benefit from routine use of low molecular weight heparin (LMWH) as postoperative DVT prophylaxis.
METHODS: We conducted a formal cost-effectiveness analysis using a decision analytic tree to represent the risk of complications under a scenario of no prophylaxis and a scenario of routine LMWH prophylaxis for 4 weeks. The two scenarios were compared for five procedures: 1) Achilles tendon repair (ATR), 2) total ankle replacement (TAR), 3) hallux valgus surgery (HVS), 4) hindfoot arthrodesis (HA), and 5) ankle fracture surgery (AFS). Outcomes assessed included short and long-term costs, quality-adjusted life-years (QALYs), and incremental cost per QALY gained. Costs were evaluated from the health care system perspective and expressed in US dollars at a 2015 price base. In the short-term, routine prophylaxis was always associated with greater costs compared to no prophylaxis.
RESULTS: For ATR, TAR, HA and AFS prophylaxis was associated with slightly better health outcomes; however, the gain in QALYs was minimal compared to the cost of prophylaxis (ICER was well above $50,000/QALY threshold). For HVS, prophylaxis was associated with both worse health outcomes and greater costs. In the long-term, routine prophylaxis was always associated with worse health outcomes.
CONCLUSIONS: We conclude that the decision to use LMWH prophylaxis should not be based solely on the type of foot/ankle surgery planned. Patient factors also need to be carefully weighed.