US population norms for the EQ-5D-5L and comparison of norms from face-to-face and online samples.

PURPOSE: Normative scores (norms) allow for comparisons between population(s) of interest and the general population, which is useful for burden of disease studies and cost-effectiveness analysis. The primary aim of this study was to estimate US visual analogue scale (EQ VAS) and utility-based norms for the EQ-5D-5L using the face-to-face sample. The secondary aim was to compare norms estimated in the face-to-face and online populations. METHODS: This study estimated population norms from two general population surveys: (a) face-to-face and (b) online. In these surveys, respondents provided their health state using the EQ-5D-5L health classifier and the EQ VAS. Descriptive statistics, including mean, standard deviation (SD), 95% confidence interval, and median for the 5L utility and EQ VAS were estimated for each sample and across relevant respondent characteristics to serve as the basis for US EQ-5D-5L norms RESULTS: Face-to-face sample respondents (n = 1134) were representative of the US adult general population. In this sample, mean (SD) utility decreased with increasing age until age 45 or greater (age 45-54: 0.816 (0.249) age 55-64: 0.815 (0.243) age 65-74: 0.824 (0.217) age 75 + : 0.811 (0.218)). With increasing age, more problems were reported on all dimensions except anxiety/depression; a smaller proportion of respondents age 65 and older reported problems with anxiety/depression (23.8%) as compared to the youngest respondents (42.1%). Online (n = 2018) mean utility and EQ VAS values were consistently lower than the face-to-face sample. CONCLUSIONS: The availability of US EQ-5D-5L norms facilitates interpretation and understanding of general population and patient health.

The validity of the EQ-5D-3L items: an investigation with type 2 diabetes patients from six European countries.

BACKGROUND: Most previous studies concerning the validity of the EQ-5D-3L items refer to applications of only a single language version of the EQ-5D-3L in only one country. Therefore, there is little information concerning the extent to which the results can be generalised across different language versions and/or different countries. Here the validity of the EQ-5D-3L items is investigated for six different language versions in six different countries. METHODS: Data came from 1341 type 2 diabetes patients (England: 289; Finland: 177; Germany: 255; Greece: 165; the Netherlands: 354; Spain: 101). The relationships of the five EQ-5D-3L items with seven different test variables (age, gender, education, previous stroke, problems with heart, problems with lower extremities, problems with eyes), were analysed for each combination of item and test variable. For each combination two logistic regression models with the dichotomised EQ-5D-3L item as dependent variable were computed. The first model contained the test variable and dummy coded countries as independent variables, the second model additionally the terms for the interaction between country and test variable. Statistically significant better fit of the second model was taken as evidence for country specific differences regarding the relationship. When such differences could be attributed mainly to one country the analyses were repeated without the data from this country. Validity was investigated with the remaining data using results of the first models. RESULTS: Due to lack of variation in the Spanish data only 31 of the originally intended 35 interaction tests could be performed. Only three of these yielded a significant result. In all three cases the Spanish data deviated most. Without the Spanish data only 1 of the 35 interaction tests yielded a significant result. With 3 exceptions, the tendency of reporting problems increased with age, female gender, lower education, previous stroke, heart problems, problems with lower extremities and problems with eyes for all EQ-5D-3L items. CONCLUSION: The results concerning the European Spanish version are ambiguous. However, the items of the English, Finnish, German, Greek and Dutch versions of the EQ-5D-3L relate in substantially the same way to the test variables. Mostly, these relationships indicate the items' validity.