Making cost assessments based on RCTs more useful to decision-makers.

The appropriateness of results from economic evaluation for allocation-decisions in health care is a point of major concern for decision-makers. Much attention has been focused on potential biases stemming form the methodological shortcomings of economic evaluation. This article adds to this and concentrates on the 'real world' relevance of results from economic evaluation as an additional step towards making results more useful to decision-makers. Being the accepted standard for economic evaluation, the RCT is used as the reference case; yet, many of the issues raised are also relevant for other research designs. Three classes of biases are examined. The first relates to the limited scope that economic analysts sometimes choose in RCTs. The second class involves the methodological aspects of RCTs and questions the 'real world' relevance of the tools with which economic analysts estimate costs on the basis of RCTs. The third class concerns the representativeness of RCT results, i.e. the generalizability of these results and their usefulness in other treatment contexts. options for limiting the potential confounding influences of these biases are discussed. A check-list is provided which should be applied by decision-makers when using constructing and describing RCTs. This will enhance the relevance of the results of economic evaluation in decision-making and improve the information basis for actual allocation decisions in health care.