Stressful life events exposure is associated with 17-year mortality, but it is health-related events that prove predictive

Objectives
Despite the widely held view that psychological stress is a major cause of poor health, few studies have examined the relationship between stressful life-events exposure and death. The present analyses examined the association between overall life-events stress load, health-related and health-unrelated stress, and subsequent all-cause mortality.

Design
This study employed a prospective longitudinal design incorporating time-varying covariates.

Methods
Participants were 968 Scottish men and women who were 56 years old. Stressful life-events experience for the preceding 2 years was assessed at baseline, 8-9 years and 12-13 years later. Mortality was tracked for the subsequent 17 years during which time 266 participants had died. Cox's regression models with time-varying covariates were applied. We adjusted for sex, occupational status, smoking, BMI, and systolic blood pressure.

Results
Overall life-events numbers and their impact scores at the time of exposure and the time of assessment were associated with 17-year mortality. Health-related event numbers and impact scores were strongly predictive of mortality. This was not the case for health-unrelated events.

Conclusions
The frequency of life-events and the stress load they imposed were associated with all-cause mortality. However, it was the experience and impact of health-related, not health-unrelated, events that proved predictive. This reinforces the need to disaggregate these two classes of exposures in studies of stress and health outcomes.