EQ-SD: a measure of health status from the EuroQol Group

In the clinical and economic evaluation of health care, the value of benefit gained should be determined from a public perspective. The objective of this study was to establish relative valuations attached to different health states to form the basis for a 'social tariff' for use in quantifying patient benefit from health care. Three thousand three hundred and ninety-five interviews were conducted with a representative sample of the adult British population. Using the EuroQol health state classification and a visual analogue scale (VAS), each respondent valued 15 health states producing, in total, direct valuations for 45 states. Two hundred and twenty-one re-interviews were conducted approximately 10 weeks later. A near complete, and logically consistent, VAS data set was generated with good test-retest reliability (mean ICC = 0.78). Both social class and education had a significant effect, where higher median valuations were given by respondents in social classes III-V and by those with intermediate or no educational qualifications. These effects were particularly noticeable for more severe states. The use of such valuations in a social tariff raises important issues regarding the use of the VAS method itself to elicit valuations for hypothetical health states, the production of separate tariffs according to social class and/or education and the appropriate measure of central tendency.

The EuroQol weighting exercise consists of three parts. In the first, the respondents state their own health using five dimensions with three levels in each, and then they rate their own health state on a visual analogue scale. In the second part, respondents attach weights to some of the possible health states. The last part contains questions about background information. The present article presents such weights derived from a sample of the Swedish population. The sample of 1000 Swedish citizens was drawn randomly from a national address register. The overall response rate was 54.2%, though 315 (31.5%) of the responses were ultimately deemed usable. Most of the health states included in the weighting exercise were well-chosen. Most of them were represented by at least one of the respondents. The respondent characteristics that had any influence on the valuation of health states in the weighting exercise was rating of own health, age and level of education, where a higher rating of own health, higher age and lower level of education resulted in higher valuations.