Cost implications of low molecular weight heparins as prophylaxis following total hip and knee replacement.

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are serious and costly complications of total hip and knee replacement surgery. The risk of these complications is significantly reduced by prophylaxis. Low molecular weight heparins (LMWH) are being used for this indication with increased frequency. The objective of this study was to assess the cost implications of LMWH for the prevention of symptomatic DVT and PE complications following total hip and knee replacement surgery. The study design was cost analysis based on utilization and the costs of medical resources for prophylaxis and treatment of DVT/PE. A retrospective hospital data set was used to assess symptomatic DVT/PE complication rates and medical resource utilization in patients receiving warfarin, other, and no prophylaxis. The results of a clinical trial were used to estimate relative reductions in risk of symptomatic DVT/PE due to prophylaxis with LMWH. The 7721 total hip and knee replacement patients analyzed were admitted in 1992 in 57 acute-care non-federal hospitals. The measurements were of incremental costs or charges expected to be saved as a result of using LMWH prophylaxis instead of warfarin prophylaxis. Prophylaxis using LMWH rather than warfarin reduces the expected total costs (charges) of treatment by $50 ($193), not including the pharmaceutical costs associated with prophylaxis. The cost reduction in favor of LMWH was sensitive to several factors, including blood monitoring costs and DVT/PE complication rates. Where a reduction of one day in hospital stay could be realized from LMWH's early onset of action, the cost (charges) reduction increased to $226 ($624). In conclusion, LMWH has the potential to offer several short- and long-term cost advantages compared with warfarin, mostly due to lower test costs associated with prophylaxis and reduced complication rates.