[Health risks due to long-term stress--night work as an example]

Multiple matched cases of shiftworkers, dayworkers and drop-outs, (N = 301) were split into four groups corresponding in age and years at work. Data concerning different parameters of health and wellbeing were collected by means of medical case histories, check-ups, questionnaires and interviews. Time contingent effects of health deterioriation were analysed. In terms of an overall score ("Health Score") in shiftworkers health was found to decrease with age markedly; the difference to dayworkers got significant from the 12th year of work exposure onwards. This finding can be ascribed to a high rate of sleep disturbances and a pronounced reduction of wellbeing (already present in younger workers) as well as to a significant increase in morbidity concerning gastrointestinal and cardiovascular ailments. Corresponding rates of doctor's consultations and drug intake increased with age and work exposure. Subjective ratings of work conditions suggest marked mental and emotional stress components. In dayworkers a destabilization of health was found which was marked for the middle age; the health score, however, was still significantly better than that of shiftworkers in all age classes. There was evidence of an excess rate for respiratory illnesses. In drop-outs less adverse conditions of health and wellbeing than in shiftworkers were found. But health was more deteriorated than in dayworkers. Having dropped out of shiftwork means an improvement of gastrointestinal and nervous symptoms; the cardiovascular disorders, however, remain high.