A comparison of United Kingdom and Spanish general population time trade-off values for EQ-5D health states

Few studies have compared preference values for health states obtained in d ifferent countries. The present study compared Spanish and United Kingdom ( UK) time trade-off values for EuroQol-5D health states. The same preference elicitation protocol was followed in both countries. Differences in values for 43 health states rated directly were analyzed using t tests, and regre ssion coefficients generated by random effects modeling were compared by ag gregating the 2 value sets and using dummy variables to analyze country eff ect by dimension and level of severity. For the milder health states, Spani sh and UK value assignation was similar; for intermediate health states, Sp anish values were both higher and lower than UK values, whereas for health states worse than death, UK values were generally higher than Spanish value s. There were statistically significant differences (P < 0.01) in values fo r 34.9% of health states rated directly, and some preference reversals betw een countries. UK raters ascribed greater importance to dimensions of pain/ discomfort and anxiety/depression, whereas Spanish raters placed more impor tance on functional dimensions of mobility and self-care. Further analysis is required: to determine how these differences affect cost-effectiveness a nd cost-utility analyses.