Psychometric Evaluation of the Health State Description Questionnaire in Chile: A Proposal for a Latent Variable Approach for Valuating Health States.

BACKGROUND: A few instruments that identify and valuate health states are based on the International Classification of Functioning, Disability and Health States of the World Health Organization. One of them is the Health State Description (HSD) questionnaire first used in the World Health Survey (WHS) initiative (HSD-WHS), whose psychometric properties have not been evaluated in Chile. Additionally, the use of latent variables for the valuation process of health states has been scarcely investigated in the context of population health metrics. We aim to evaluate the psychometric properties and factorial structure of the HSD-WHS for Chile and describe a latent variable method for valuating health states associated with diseases. METHODS: We used data from the second Chilean National Health population-based survey from 2009 to 2010 (N = 5293). We explored the factorial structure of the HSD-WHS through exploratory and confirmatory factor analyses, the reliability, and the discriminant validity of the latent variable of disability. Disability weights for diseases were calculated using a linear regression model. RESULTS: We found an adequate goodness of fit for a second-order model with 9 factors corresponding to disability domains (Tucker-Lewis index = 0.99, comparative fit index = 0.99, root mean square error of approximation = 0.060), and good reliability estimates (standardized α = 0.91). The rescaled (between 0 and 100) latent variable of disability showed significant difference according to the explored variables. We estimated disability weights for the following: (1) depressive episode, 13.6 (12.1-15.2), (2) hypertension, 1.6 (0.0-3.3), and (3) diabetes, 5.0 (2.5-7.4). CONCLUSIONS: This study supports the use of the HSD-WHS questionnaire in the Chilean population and a latent variable approach for valuating health states associated with diseases.

Population norms for the EQ-5D-3L: a cross-country analysis of population surveys for 20 countries.

This study provides EQ-5D population norms for 20 countries (N = 163,838), which can be used to compare profiles for patients with specific conditions with data for the average person in the general population in a similar age and/or gender group. Descriptive EQ-5D data are provided for the total population, by gender and by seven age groups. Provided index values are based on European VAS for all countries, based on TTO for 11 countries and based on VAS for 10 countries. Important differences exist in EQ-5D reported health status across countries after standardizing for population structure. Self-reported health according to all five dimensions and EQ VAS generally decreased with increasing age and was lower for females. Mean self-rated EQ VAS scores varied from 70.4 to 83.3 in the total population by country. The prior living standards (GDP per capita) in the countries studied are correlated most with the EQ VAS scores (0.58), while unemployment appeared to be significantly correlated in people over the age of 45 only. A country's expenditure on health care correlated moderately with higher ratings on the EQ VAS (0.55). EQ-5D norms can be used as reference data to assess the burden of disease of patients with specific conditions. Such information, in turn, can inform policy-making and assist in setting priorities in health care.