Comparing the EQ-5D-5L utility index based on value sets of different countries: impact on the interpretation of clinical study results.

For each of the 3125 possible health states the difference between the country with the highest index and the country with the lowest index was calculated. The median difference was 0.417 across the health states. When analyzing multinational clinical studies, country-specific value sets should be used to evaluate treatment effects. Additional country-specific analyses are needed.