Aggregating health state valuations.

It is now recognized that preference-based measures of health status have an important role to play in determining priorities in health care. A number of methodological and ethical issues have been raised, but one that has as yet received little attention is the question of how individual responses should be aggregated when attempting to express the valuations of a given group. In a recent study of over 3000 members of the British general public, valuations were elicited for health states defined in terms of the EuroQol Descriptive System using the time trade-off method. A EuroQol 'tariff' of valuations has been generated which, because of the methodology employed, provides a good approximation of mean values. The purpose of this paper is to present a tariff based on median values. The nature of the distributions of values results in a median-based tariff which, compared to the mean-based one, has higher values for less severe states and lower values for more severe states. This is likely to have important implications for resource allocation decisions.