Intimations of mortality: perceived age of leaving middle age as a predictor of future health outcomes within the Whitehall II study

Objectives: to determine the association between the subjective rate of ageing and future health outcomes. Design: prospective cohort study (Whitehall II study). At the third phase of the study (1991-1993), participants were asked at what age they think most people leave middle age. Participants were followed until the end of phase 5 (19972000), so that mean length of follow-up was 7 years. Setting: London based office staff in 20 civil service departments. Subjects: 5,262 male and 2,277 female civil servants aged 40-60. Measures: validated new cases of coronary heart disease and health function, measured by the SF-36 General Health Survey, at phase 5. Results: perceived age of leaving middle age increased with age, self-rated health and grade of employment, and was higher in women. Adjusting for age and sex, people who believed middle age ends less than or equal to60 years, compared to 70 years, were at higher risk for coronary heart disease (HR = 1.43, 95% CI = 1.05-1.94), fatal coronary heart disease and non-fatal myocardial infarction (HR = 1.52, 0.95-2.42), and poor physical (OR = 1.29, 1.10-1.50) and mental (OR = 1.25, 1.07-1.45) functioning during follow-up. Adjustment for self-rated health, employment grade, health behaviours, social networks, control and baseline health status, respectively, did not eliminate these associations. Conclusions: the reported age at which middle age ends predicts future health outcomes. We hypothesise that perceived end of middle age acts as a general summary of the subjective rate of ageing.