Meta-analysis has become an increasingly accepted research tool for producing overviews of the results of clinical studies. Recently, there has been a rapid increase in the number of economic evaluations performed, and there is both the need and the potential to produce overviews for policy makers. OBJECTIVE: The purpose of this research was to investigate whether standard meta-analytical approaches (as applied to clinical data) could be applied to economic evaluations. As a case-study, an economic meta-analysis (EMA) was conducted of cost-effectiveness analyses involving antithrombotic agents (standard heparin, LMW heparin, warfarin) as prophylaxis against deep-vein thrombosis (DVT) following total hip arthroplasty. METHODS: The EMA was based on an adapted Cochrane Review framework. The objectives were (i) to determine whether prophylaxis is cost-effective versus no prophylaxis; (ii) to determine the most cost-effective agent and (iii) to explore differences in cost-effectiveness between settings. Prior to the literature search (databases/handsearches), selection criteria were specified. Each eligible study was assessed for economic and clinical quality using modified checklists, and various clinical (e.g. DVT, PE rates; mortality) and economic variables (e.g. drug acquisition costs, treatment costs) were extracted and pooled. All costs were standardised to US dollars (1997). RESULTS: 35 economic studies were retrieved, of which 14 met the criteria for inclusion (5=US,4=Sweden,2=Canada,2=Denmark,1=UK). Economic quality was generally high (71-86%), but the clinical quality was less certain (3’A’s, 4‘B’s, 7 ‘ungradeable’). Although considerable variability existed across studies, the pooled analysis showed an overall reduction in both costs and DVT, PE and mortality rates associated with prophylaxis versus no prophylaxis. In preventing DVT and PE, LMW heparin was more effective than standard heparin, but similar to warfarin. Although the acquisition cost of LMW heparin was greater than both alternatives, this was offset by the reduced treatment cost for complications. Costs tended to be higher in the US. CONCLUSION: From this case-study, we have employed a systematic approach for reviewing economic evaluations, and have highlighted ways the standard meta-analytical methodology would need to be adapted to achieve reliable and useful overviews.