On the Sensitivity of Healthy Life Years to the Health Reporting Style

Paola DiGiulio , Vienna Institute of Demography, Wittgenstein Centre (IIASA, OeAW, University of Vienna)
Marc Luy , Wittgenstein Centre (IIASA, OeAW, Univ. Vienna)
Yuka Minagawa, Sophia University

Comparing self reported health across different populations presents the well known challenge that indivuals are different in their reporting styles. If the differences in reporting styles – usually referred to as differential item functioning, DIF - are sufficiently large, there might exist bias in comparison of populations, e.g. in the country rank ordering of populations health outcomes. In this paper we address this issue and we estimate DIF-adjusted healthy life years (HLY) at different ages by means of the Sullivan method, with the global activity limitations indicator (GALI) as underlining health question. For computing the adjustment factors, we use the information contained in the health-related anchoring vignettes collected in the first wave of the SHARE surveys in 2004. Data on self reported health status stem from EUSILC 2005, while life tables were taken from Human Mortality Datadase (HMD). Results show that different reporting styles across European countries affect the ranking of countries by HLY, and suggest that caution should be used in using the HLY indicators to assess policy targets.

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 Presented in Session 20. Adding Healthy Life Years to Our Lives