Temperament as a potential predictor of mortality: evidence from a 41-year prospective study.

Psychological factors were hypothesized to influence mortality, in particular, early versus later mortality. To explore the relationship between temperament, a psychological factor, and mortality in a prospective study of 1337 medical students, we constructed a measure portraying three temperament types, using latent class analysis. Death occurred in 113 subjects over 25-41 years of follow-up. In univariate survival analysis, subjects tending to direct tension "inward" when under stress ("Tension-In") had a higher risk of mortality than "Tension-Out" or "Stable" types. These associations persisted after adjustment for age, smoking, cholesterol level, and Quetelet Index. The relative risk (RR) of mortality for Tension-In was 1.56 (95% confidence interval, 1.00-2.44) compared with the Stable group. The risk was due entirely to the excess risk in persons under 55 years of age (RR, 2.59; 95% confidence interval, 1.46-4.62); the corresponding risk of death in older persons was 0.66 (0.30-1.48). Thus temperament is a significant risk factor for mortality, in particular, premature death.