ESTIMATING COUNTRY-SPECIFIC COST-EFFECTIVENESS FROM MULTINATIONAL CLINICAL-TRIALS

Because costs and outcomes of medical treatments may vary from country to country in important ways, decision makers are increasingly intere sted in having data based on their own country's health care situation s. This paper proposes methods for estimating country-specific cost-ef fectiveness ratios from data available from multinational clinical tri als. It examines how clinical and economic outcomes interact when esti mating treatment effects on cost and proposes empirical methods for ca pturing these interactions and incorporating them when making country- specific estimates. We use data from a multinational phase III trial o f tirilazad mesylate for the treatment of subarachnoid haemorrhage to illustrate these methods. Our findings suggest that it is possible for meaningful country-by-country differences to be found in such trial d ata. These differences can be useful in informing reimbursement, utili zation, and other decisions taken at the country level. (C) 1998 John Wiley & Sons, Ltd.