Self-rated health and mortality: short- and long-term associations in the Whitehall II study

To determine if self-rated health (SRH), a single-item measure of health status where individuals are asked to rate their own health, predicts mortality in a middle-aged sample and if the predictive ability of SRH diminishes with time. Data (6316 men and 3035 women) are drawn from the Whitehall II study. SRH and covariates were measured at baseline (1985-1988) when the average age of individuals was 44.5 years (SD = 6.1). The mortality follow-up was available for a mean of 17.5 years and was classified as having occurred in the first 10 years or the subsequent follow-up period (range 6 to 9 years). The association between SRH and mortality was assessed using a Cox regression model with relative index of inequality (RII) to summarize associations. There were no sex differences in the association between SRH and mortality in either the short (p = .39) or the long term (p = .16). Sex-adjusted short-term association (RII = 3.80; 95% confidence interval (CI) 2.28, 6.35) was significantly (p = .004) stronger than the long-term association (RII = 1.56; 95% CI 1.04, 2.34). Explanatory variables accounted for 80% of the SRH-mortality association in men and 29% in women. SRH predicts mortality equally well in men and women. However, the covariates explained a much larger proportion of the SRH-mortality relationship in men compared with women. In this middle-aged cohort, SRH predicts mortality strongly in the short term but only weakly in the long term.