Research Team: Ferrer, M (IP), Alonso, J; Cunillera, O; Garin, O; Herdman, M; Pardo, Y; Rajmil, Ll, Schmitd S, Vilagut, G.
- Background: Traditionally, health surveys frequently included basic subjective measures of health, such as the item on perceived health status. The extension of health related quality of life measures in recent years has led to greater use of multidimensional instruments in population health surveys. The Catalan Health Interview Survey (CHIS) was one of the first population health surveys to include a generic measure of HRQL (the EQ-5D) in consecutive editions of the same survey. Moreover, the most recent edition of the CHIS included the SF-12 in a subsample of adults and the KIDSCREEN-10 for children.
- Methodology: Sampling was based on a two-stage procedure based first on health care regions and then on random sampling of participants within municipalities. Representative samples of 15 000, 8 400 and 18 126 participants (12 567, 7 157 and 15 926 >15 years old) were included in the 1994, 2002, and 2006 editions, respectively. Data were also collected on socio-demographic characteristics, perceived health status, health related behaviours, and use of health services. Analyses were carried out using SUDAAN version 8.0. Standard errors (SE) and significance of tests were estimated using the Taylor series method and a With Replacement (WR) design given that the sampling fraction in the first stage was small. Sample characteristics were described by calculating the raw number of participants in each group together with weighted percentages and their standard errors.
- Results: EQ-5D index scores decreased (deteriorated) between 1994 and 2006, although differences among 1994 and 2006 editions were only significant in those aged 75 years or over. A published study in Sweden showed similar results for the period 1998-2004. The impact of chronic conditions on HRQL generally remained stable, though the impact of hypertension and depression decreased slightly and the impact of stroke decreased significantly between 1994 and 2006. Although the EQ-5D was found to be more sensitive than the SF6D with regard to the impact of chronic conditions on health, the SF-12 was a viable alternative to the ED-5D because of the complementary information provided by the mental and physical health summaries.
Key words: Health surveys, HRQL, EQ5D, SF-12.
Funding: Departament de Salut de la Generalitat de Catalunya.