Shiftwork, stress, and psychosomatic complaints: a comparison between workers in different shiftwork schedules, non-shiftworkers, and former shiftworkers

In a questionnaire study of 3446 blue-collar male workers in the chemical industry of the Federal Republic of Germany, shift- and non-shiftworkers were compared for reported health and stress at work. There were three groups of non-shiftworkers: former shiftworkers who left shiftwork because of a physician's advice, former shiftworkers who were not so advised, and never-shiftworkers. Both shiftworkers and former shiftworkers who left for health reasons showed a higher degree of reported ill health than never-shiftworkers and former shiftworkers who had left for other reasons than health. The results are consistent when stress at work and other potentially confounding factors are controlled. However, stress at work is an important predictor of ill health independent of shiftwork. Furthermore, a rapidly rotating 12-hour shift system (rotating every 2 to 3 days) as compared with a slower rotating 8-hour shift system (rotating every 5 to 7 days) showed no significant differences in workers' ill health when stress at work and skills were controlled.