Comparing the efficiency of national health systems: a sensitivity analysis of the WHO approach.

The World Health Organization (WHO) has used econometric methods to measure the efficiency of health care systems. We assess the robustness of WHO results to definitions of efficiency and statistical procedures. Originally analysed by the WHO, the data are for 1997 (50 countries) and 1993-1997 (141 countries). The efficiency of each country in promoting population health is estimated after taking into account health care expenditure, all other expenditure and education levels. Efficiency scores are compared under different definitions of efficiency and different estimation methods. The results show that the country rankings and efficiency scores are sensitive to the definition of efficiency and choice of model specification. We conclude that econometric methods can yield insights into complex socioeconomic phenomena. However, the lack of robust results to reasonable alternative specifications suggests that it is premature to use the methods adopted by the WHO to construct league tables of health systems.