Economic analysis based on multinational studies: methods for adapting findings to national contexts

Background Health economic parameters are increasingly considered as variables in health care decisions, but decision makers are interested in country-specific evaluations. However, a large number of studies are performed in foreign countries or in a multinational setting, which limits the transferability to a single nation's context. Objective The present analysis summarises several of the most common international methods for generating health economic analyses based on clinical studies from different settings. Methods A narrative literature review was performed to identify potential reasons for limited transferability of health economic evaluation results from one country to another. Based on these results, we searched the methodological literature for analytic approaches to handle the restrictions. Additionally we describe the possibility of transferring foreign economic study results to the country of interest by matching trial data with routine data of national databases. Results The main factors for limited transferability of health economic findings were found in country-specific differences in resource consumption and the resulting costs. These differences are affected by a number of influencing cofactors (demography, epidemiology and individual patient's factors) and the overall health care system structures (e.g. payment systems, health provider incentives). However, despite the limitations country-specific health economic assessments could be realised using the pooled/split analyses approach, some statistical approaches and modelling approaches. Conclusion A variety of methods for identifying and adjusting country-specific differences in costs, effects and cost-effectiveness was established during the past decades. Multinational studies will continue to play a crucial role in the evaluation of cost-effectiveness at national levels. It seems likely that the growing interest in multinational studies will lead to continued developments in adaptation methods.