Job insecurity and prognosis after myocardial infarction: the SHEEP Study

Background: The prognostic role of job insecurity in coronary heart disease is unknown. We aimed to analyze whether job insecurity predicts mortality and recurrent events after a first acute myocardial infarction (AMI).

Methods: We studied non-fatal AMI cases involved in the Stockholm Heart Epidemiology Program who were in paid employment and younger than 65 years (n=676). Shortly after their AMI, patients completed a questionnaire about job insecurity, demographic, work-related, clinical and lifestyle factors and participated in a clinical examination three months after discharge from the hospital. They were followed for 8.5 years for mortality and cardiovascular events.

Results: After adjusting for previous morbidity, demographic and work-related factors, job insecurity was associated with an increased risk of the combined endpoint of cardiac death and non-fatal AMI, of total mortality and of heart failure; the hazard ratios (HR) and the 95% confidence intervals (CI) were 1.50 (1.02-2.22), 1.69 (1.04-2.75) and 1.62 (1.07-2.44), respectively. Similar associations, but with less statistical power were observed between job insecurity and cardiac death (HR (95% CI): 1.57 (0.80-3.09)) and stroke (HR (95% CI): 1.46 (0.71-3.02)), respectively. Adjustment for potential mediators, i.e. sleep problems, health behaviour, hypertension, blood lipids, glucose, inflammatory and coagulation factors did not alter considerably the relationship between job insecurity and the combination of cardiac mortality and non-fatal AMI.

Conclusions: Our results suggest that job insecurity is an adverse prognostic factor in patients with a first AMI. Future studies are needed to confirm this finding and to determine the mechanisms underlying the observed relationship.