Monitoring sleep hours using a sleep diary and errors in rotating shiftworkers.

The sleep hours of male workers on rotating shift schedules were measured using a sleep diary. The mean age of workers was 40.3 years. Work shifts were rotated on a weekly basis and fell into three periods: morning, evening, and night. One working week consisted of 5 days. Errors that occurred during the work were also evaluated. A significant difference in the mean length of sleep was observed for each of the three shifts. Compared with the morning shift, the length of sleep for workers working evening and night shifts were significantly longer. The error of workers was not recognized in three rotating shift schedules in the survey period. Rotating shiftwork affects the amount of sleep, but not the event of error.