Cost-of-illness studies. Useful for health policy?

A sample of cost-of-illness (COI) studies was reviewed, which included studies for specific diseases ('specific' studies) as well as those for the entire range of diseases ('general' studies). Theoretically, COI studies may deliver suitable information for health policy and rational healthcare spending. In practice, however, the informative value of 'specific' prevalence-based COI studies is very limited. A static picture of costs is presented in these studies, as trends in costs are not being described or explained by factors such as demography, epidemiology and technology. No practical link is offered between COI estimates and economic evaluation. Incidence-based COI studies can provide more relevant information for economic evaluation studies. It appears more useful to perform general COI studies, as these provide comparable estimates of disease costs and put cost estimates in a total healthcare perspective. Compared with specific COI studies, general COI studies better facilitate the analysis and projection of trends in costs, for example due to aging.