Self rated health:: Is it as good a predictor of subsequent mortality among adults in lower as well as in higher social classes?

Study objective - To analyse the predictive power of self rated health for mortality in different socioeconomic groups. Design, setting, participants - Analysis of mortality rates and risk ratios of death during follow up among 170 223 respondents aged 16 years and above in the Swedish Survey of Living Conditions 1975-1997, in relation to self rated health stated at the interview, by age, sex, socioeconomic group, chronic illness and over time. Main results - There was a strong relation between poor self rated health and mortality, greater at younger ages, similar among men and women and among persons with and without a chronic illness. The relative relation between self rated health and subsequent death was stronger in higher than in lower socioeconomic groups, possibly because of the lower base mortality of these groups. However, the absolute mortality risk differences between persons reporting poor and good self rated health were similar across socioeconomic groups within each sex. The mortality risk difference between persons reporting poor and good self rated health was considerably higher among persons with a chronic illness than among persons without a chronic illness. The mortality risk among persons reporting poor health was increased for shorter (<2 years) as well as longer (10+ years) periods of follow up. Conclusions - The results suggest that poor self rated health is a strong predictor of subsequent mortality in all subgroups studied, and that self rated health therefore may be a useful outcome measure.