Effects of shiftwork on lifestyle and mental health status of employees of a major Japanese electrical manufacturer

To examine the effect of shiftwork on lifestyle and mental health, a self-administered questionnaire survey was conducted among employees of a leading electrical appliances manufacturing company in Japan. The questionnaire included eight health practices recommended by Morimoto, the General Health Questionnaire-28 (GHQ-28) and demographic variables. Considering the effects of type of occupation, working hours and gender, analysis was focused on 295 male blue-collar mere employees working less than 8 hours per day and engaged in daytime work or two-shift work