Sleep habits and factors associated with short sleep duration among Japanese high-school students: A community study

To clarify the sleep habits, and predictors thereof, in Japanese high-school students, a community study was conducted. A total of 3833 students were selected randomly from the 34 full-time high schools in two suburban cities in Japan. The response rate was 90.7% (n = 3478). The students completed the Japanese version of the Pittsburgh Sleep Questionnaire Index (PSQI-J), the Japanese version of the 12-item General Health Questionnaire (GHQ12-J), and a questionnaire on sociodemographic characteristics, daily life, domestic situations, and perceived physical health. Mean bed and rise times were found to be 00:03 and 06:33 h, respectively, resulting in a sleep duration of 380.0 min. A multivariate logistic regression analysis revealed that a short sleep duration (i.e. less than 6 h; prevalence: 25.6%) was significantly associated with a later bedtime, a higher global PSQI-J score, an earlier rise time, being female, a longer study duration outside school hours, and a longer commuting duration, but not with a higher GHQ12-J score. Short sleep duration in Japanese high-school students is associated with their lifestyle as well as sleep problems, but not with psychosomatic problems.