Psychosocial risk factors for myocardial infarction among Swedish railway engine drivers [corrected].

Background: Several earlier investigations have found an increased incidence of myocardial infarction among male drivers and, not least, among railway engine drivers. In a previous study we found that increased serum cholesterol, blood pressure or tobacco smoking did not explain this increased risk.

Objective: To investigate psychosocial factors and primarily work-related factors among male engine drivers.

Design: Engine drivers were compared with random population samples in a cross-sectional study.

Method: Two thousand three hundred and eighteen engine drivers aged 25-59 years were compared with 331 randomly selected men who were mainly from the Göteborg MONICA population study. Job demands and job decision latitude as well as social support were the main factors compared.

Results: Job demands were reported as being significantly lower by both younger and older engine drivers compared to their referents (P = 0.002 and P = 0.0001, respectively). Decision latitude was reported as being lower by both younger and older engine drivers than among controls (P = 0.0001 for both groups). Engine drivers experienced deficient support from their superiors compared to the referents (P = 0.0001 for younger as well as older engine drivers). Low decision latitude was associated with significantly higher diastolic blood pressure (r = -0.11 and P = 0.0001), but otherwise there were no significant relationships between psychosocial work characteristics and somatic risk factors.

Conclusions: The combination of low decision latitude and low social support seems to be a key factor in the increased risk of myocardial infarction among railway engine drivers. They generally undertake shift work which may be an additional risk factor for myocardial infarction.