A cross-national perspective on cost of illness: a comparison of studies from The Netherlands, Australia, Canada, Germany, United Kingdom, and Sweden.

All Western health systems are in search of efficiency. Cost of illness (COI) studies can contribute to the efficiency debate by elucidating the relation between health expenditure and health status and population demography. Since the purpose of COI data being summarized in the OECD Health Data publications is to facilitate cross-national comparisons, it is important to assess the comparability. We compared COI data from six countries at macrolevel of total health expenditure and disaggregated the data from four countries to sectors such as hospitals, drugs, health professionals, and residential care. Although the distribution of health expenditure over major diseases showed similar patterns in all countries, overall comparability was bad. We conclude that the current scope of COI studies is bound to national levels because health care systems dominate the magnitude and distribution of health expenditure. Cross-national comparisons may be possible if data and methods are standardized, and COI estimates are made for a common comparable package.