The global activity limitation indicator and self-rated health: two complementary predictors of mortality

BACKGROUND The purpose of this study is to compare the ability of the Global Activity Limitation Indicator (GALI) and self-rated health (SRH) to predict all-cause mortality in the general adult population. METHODS We linked the 2001 Belgian Health Interview Survey with mortality and migration registers 2001-2010. The baseline sample included 8,583 individuals aged 15 years and older. Poisson regression models were used to estimate the effect of the GALI and SRH on mortality rate during follow-up. We investigated the impact of gender, age, education and follow-up period on the association between the GALI/SRH and mortality. RESULTS The GALI and SRH were strong and complementary predictors of mortality in the Belgian adult population. Although the two global instruments shared some traits, they predicted mortality concurrently, with some indication of a somewhat stronger effect for SRH. We found neither significant differences between men and women, nor between education groups. The predictive effect of the GALI and SRH slightly decreased over time and the predictive effect of SRH slightly decreased with age. CONCLUSIONS Our findings suggest that the GALI and SRH are useful and complementary measures for assessing the health and functional status of adults in population surveys.