ABSTRACT
To quantify health states, these must be described and classied in terms of seriousness and assigned meaningful values (variously called utilities, strength of preference, index, or weights). The rst step, thus, is to clarify the concept of health status. Essentially an umbrella concept, it covers independent health domains that together capture the rather loosely conceived notion of health-related quality of life (HRQoL). The second step is to assign a value to the health-state description by means of an appropriate measurement procedure. In the past, several measurement models have been developed to quantify subjective phenomena, and some of these models have found their way into the valuation of health states. Although the scientic enterprise of measuring health states has been going on for about 40 years, there are still concerns about its validity.
