Sleep problems in white-collar male workers in an electric equipment manufacturing company in Japan

In order to clarify poor sleep habits and prevalence in sleep problems (disturbances) of healthy male white-collar workers and the relationship of these to age and job type, a total of 1,161 Japanese employees of an electric equipment manufacturing company (aged 23 to 59, mean 37 years) were surveyed by means of a mailed questionnaire. The workers were asked about eleven sleep habits. They were also divided into four groups according to age and job type: 23-29 (n = 226), 30-39 (n = 597), 40-49 (n = 225) and 50-59 (n = 113); managerial (n = 209), professional (n = 336), technical (n = 475) and clerical (n = 134). In this study, the sleep problems were defined as who had at least one of the following four poor sleep habits: 1) taking more than 30 minutes to fall asleep, 2) awakening during sleep (ADS) almost every day, 3) early morning awakening (EMA) almost every day, and 4) excessive daytime sleepiness (EDS) at work almost every day. Analyses showed that sleep problems were present in 26.0% of workers; the problems were most serious among workers aged 50 years and more (36.0%) which may be due to a significant increase in the prevalence rate of EMA. The results revealed that sleep problems are common in male white-collar daytime workers. The findings also suggest a need for increased attention to sleep problems in older workers and younger ones with EDS at work.