The Whitehall study performed in the 1980s showed that chronic work stress was associated with increased risk of coronary heart disease especially in men under 50 years old. This was also seen in the INTERHEART study which found that stress at work was associated with more than twice the risk of heart attack. The Womens Health Study also confirmed that the effect of stress on heart disease was not limited to men.
Last October The Lancet published a large, individual patient-level meta-analysis of 197473 European men and women without pre-existing coronary heart disease to try and investigate the effect of job strain on development of coronary heart disease. In the study 15% of partipants reported job strain which might be seen as a relatively low overall level of stress. The study assessed both the demands placed on the workers and the degree of control they had over their work. Four groups were identified. Low job strain (low demands/high control), passive (low demands/low control), active (high demands/high control) and high strain (high demands/low control).
Compared to the low job strain group, the high control/high demands group did not have increased risk of coornary heart disease. In contrast those workers with low demand/low control jobs had increased risk and the risk was even higher in those with doing jobs with high demands and low control.
These results indicate that it is the degree of control a worker has over the demands placed on him or her that determines whether the job increases the risk of coronary disease. A high work pace is not necessarily a stressor if the worker has control. A difficult task might be seen as a challenge rather than being excessively strenuous. Much of this work was carried out in industrial settings and the modern world of work is different and other factors such as the effort-reward imbalance model and job insecurity are likely to be of major importance in the future.
So when a person asks: Did stress cause my heart attack? More than a simple yes or no answer is required. You need to understand what job they have been doing and at what level. Getting an idea of the degree of control the individual had to regulate the demands of the job is critical in understanding the role of stress in heart disease.
Job Strain and Coronary Heart Disease - Lancet
Whitehall Study - Stress & Health Study
Job Strain, Job Insecurity, and Incident Cardiovascular Disease in the Women’s Health Study: Results from a 10-Year Prospective Study