Validity of the EQ–5D–5L and reference norms for the Spanish population
Background and objective
The EuroQol 5 dimensions 5 levels (EQ–5D–5L) is the new version of EQ–5D, developed to improve its discriminatory capacity. This study aims to evaluate the construct validity of the Spanish version and provide index and dimension population-based reference norms for the new EQ–5D–5L.
Data were obtained from the 2011/2012 Spanish National Health Survey, with a representative sample (n = 20,587) of non-institutionalized Spanish adults (≥ 18 years). The EQ–5D–5L index was calculated by using the Spanish value set. Construct validity was evaluated by comparing known groups with estimators obtained through regression models, adjusted by age and gender. Sampling weights were applied to restore the representativeness of the sample and to calculate the norms stratified by gender and age groups. We calculated the percentages and standard errors of dimensions, and the deciles, percentiles 5 and 95, means, and 95% confidence intervals of the health index.
All the hypotheses established a priori for known groups were confirmed (P < 0.001). The EQ–5D–5L index indicated worse health in groups with lower education level (from 0.94 to 0.87), higher number of chronic conditions (0.96–0.79), probable psychiatric disorder (0.94 vs 0.80), strong limitations (0.96–0.46), higher number of days of restriction (0.93–0.64) or confinement to bed (0.92–0.49), and hospitalized in the previous 12 months (0.92 vs 0.81).
The EQ–5D–5L is a valid instrument to measure perceived health in the Spanish-speaking population. The representative population-based norms provided here will help improve the interpretation of results obtained with the new EQ–5D–5L.
KeywordsEuroQol EQ–5D–5L Health-related quality of life Health status Utilities Questionnaires Reference values Validity
We acknowledge Aurea Martin for helping us in the English editing process and supervision of this manuscript.
GH analyzed and interpreted the data, drafted, and critically revised the manuscript and did the statistical analysis. OG provided supervision, conceived, and designed the study, and critically revised the manuscript. YP and GV analyzed and interpreted the data, and critically revised the manuscript. AP analyzed and interpreted the data, and did the statistical analysis. MS, MN, LR, IG, YR, and JC interpreted the data and critically revised the manuscript. JA provided supervision, conceived and designed the study, interpreted the data, and critically revised the manuscript. MF obtained funding, provided supervision, conceived and designed the study, interpreted the data, and critically revised the manuscript.
This study has been funded by grants from the Generalitat de Catalunya (2017 SGR 452 and 2014 SGR 748) and the Instituto de Salud Carlos III FEDER, (PI12/00772).
Compliance with ethical standards
Conflict of interest
All authors declare that they have no competing interests.
The Spanish National Health Survey is a statistical operation included in the National Statistical Plan. The agency responsible for the survey is the Ministry of Health, Social Services and Equality and it is performed jointly with the National Statistics Institute according to the 2000 revision of the Helsinki Declaration.
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