The impact of using different tariffs to value EQ-5D health state descriptions: an example from a study of acute cough/lower respiratory tract infections in seven countries.

When using the EQ-5D in European cross-national studies, there is no consensus over whether the European value set (EVS), country specific value sets (CVS) or UK value set (UKVS) should be used. Data on health outcomes were collected in 7 countries. EQ-5D index scores were generated for each country using all three value sets. QALYs gained over 4 weeks based on EQ-5D scores were also generated in order to investigate the implications for cost-utility analysis. EQ-5D scores obtained using the EVS were similar to values obtained using the CVS and UKVS in all countries. CVS-based EQ-5D scores were on average associated with a smaller baseline-to-week 4 change/improvement in all countries (except in Wales and Belgium) while UKVS-based EQ-5D scores showed the largest improvement over the same period for every country. With regards to cost-utility analysis, the results suggest that in most countries (with the exception of Belgium and Finland), using different tariffs to value EQ-5D would not have made a difference to the decisions based on the results of cost-utility analysis.