The study examined the possible link between job control factors and heart attacks, acute myocardial infarction, among 7,663 private sector employees.
"The risk of MI was about 1.8 times higher in a disorganized setting than in an organized setting. Clear organization of work tasks matters," said lead study author Ari Vaananen, from the Finnish Institute of Occupational Health in Helsinki.
Although it has long been known that risk factors such as smoking and a lack of exercise can lead to poor cardiac health, the new study finds that characteristics of a job, such as an employee's lack of control, job awareness, unexpected changes, job strain and stress, could also lead to poor cardiac health.
"We looked at the measure of predictability, how an employee views the clarity of work goals and work roles, their ability to foresee work problems and how significant work disturbances interrupt the work process and outcome." Vaananen said.
The researchers sent questionnaires to 12,173 employees in the multinational forest industry who had worked for their company for at least 24 months and who were initially free of heart disease. In all, 9,292 employees, primarily blue-collar workers, responded.
The researchers looked at demographics, psychological distress, medical conditions and lifestyle risk factors.
During the 17-year follow-up period, 56 employees died of acute myocardial infarction and 316 had nonfatal events.
Joan Gillman is the director of special industry programs at the School of Business at University of Wisconsin-Madison, said: "Not knowing what is expected in the workplace is stressful."
Gillman said that educating the work force is important to improved predictability.
"The more that employees know what is expected of them and are given the proper training, the less stressful it is for them," Gillman said.
The study appears in the December issue of the American Journal of Public Health.