Association between long working hours and sleep problems in white-collar workers

摘要

The purpose of this study is to examine the association between long work hours and sleep disturbance among white-collar workers. We evaluated 1510 male white-collar full-time employees, between the ages of 18 and 59years, using a comprehensive sleep quality questionnaire, the Pittsburgh Sleep Quality Index (PSQI). All subjects worked in a light metal products factory in Japan. The mean number of monthly overtime work hours was determined using data from the previous 6months from timecard records. Subjects were divided into five groups based on quintiles of the mean number of monthly overtime work hours: 26hmonth -1; ≥26 but 40; ≥40 but 50; ≥50 but 63; and 63. Leisure time physical activity, drinking habits just before sleep, presence of family/partner and health status were used as confounding factors in the multiple regression model. The prevalence of short sleep hours, impairment of sleep efficiency and daytime dysfunction among seven components of PSQI increased, in a dose-response relationship, with overtime work hours. The prevalence of high global score (5.5 points) was highest in workers with overtime hours ≥50h week -1. The odds ratios after adjustment for confounding factors for high global score using less than 26h as a reference group were 1.67 for workers with ≥50h and 63h, and 1.87 for workers with 63h and more. To conclude, the present results suggest that long work hours correlate with reduced sleep quality in a dose-response manner.