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

ABSTRACT

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.