ECONOMICS OF THROMBOPROPHYLAXIS IN TOTAL HIP-REPLACEMENT SURGERY

In 1997, 50 000 hip replacements will be performed in the UK, and over I million worldwide. Venous thromboembolism is the most frequent seri ous complication following joint replacement: its effective and econom ic management is essential. Antithrombotic prophylaxis can be used to reduce the incidence of venous thromboembolic disease, which presents as either deep vein thrombosis or pulmonary embolism. A number of publ ished studies have shown that prophylaxis against venous thromboemboli sm is financially beneficial in terms of reduced diagnostic and treatm ent costs. Cost-effectiveness studies have provided a comparison of th e costs and consequences resulting from alternative prophylactic progr ammes.This article reviews the epidemiology of venous thromboembolism after total hip replacement, prophylaxis against it and a model for co st-effectiveness analysis. Its aim is to highlight inadequacies in the available data and areas of uncertainty within the model that require further research. Pharmacoeconomic studies published to date have all used a similar framework to allow prophylactic options to be compared . However, assumptions made about the frequency of clinical disease ha ve varied widely between studies. This degree of uncertainty calls int o question the validity of reported incremental cost savings between t reatments, Some studies have also failed to address the cost of compli cations resulting from the prophylactic method under consideration.Fut ure studies must carefully consider the validity of their models, unde rstand the limitations on current knowledge of outcome rates, and care fully consider all outcomes (both beneficial and detrimental) that res ult from the intervention.