In search of a 'pan-European value set'; application for EQ-5D-3L.

Objectives: Country-specific value sets for the EQ-5D are available which reflect preferences for health states elicited from the general population. This allows the transformation of responses on EQ-5D to health state utility values. Only twelve European countries possess country-specific value sets and no value set reflecting the preferences of Europe exists. We aim to estimate a 'pan-European' value set for the EQ-5D-3L, reflecting the preferences for health states of the European population that could help to evaluate health care from the perspective of the European decision-maker.

Methods: We systematically assessed and compared the methodologies of available EQ-5D-3L time trade-off (TTO) value sets from twelve European countries: Denmark, France, Germany, Hungary, Italy, Netherlands, Poland, Portugal, Romania, Slovenia, Spain and UK. Using their published coefficients, a dataset with utility values for all 243 health states was simulated. Different modelling techniques and model specifications including interaction terms were tested. Model selection was based on goodness-of-fit criteria. We also explored results with application of population size weights.

Results: Methodological, procedural and analytical characteristics of the included EQ-5D-3L valuation studies were quite comparable. An OLS based model was the preferred model to represent European preferences. Weighting with population size made little difference.

Conclusions: EQ-5D-3L valuation studies were considered of sufficient comparability to form the basis for a new 'pan-European' value set. The method used allows for an easy update when new national value sets become available.