Background: Sleep debt attributable to short sleep duration among adolescents is associated with a wide range of detrimental physical and mental health outcomes.
Objective: This cross-sectional study was conducted to assess sleep/wake patterns among high school students based on the perspective of sleep debt and to explore sleep-promoting behaviors for alleviating sleep debt, late bedtime and insufficient sleep.
Methods: A total of 2,195 students in five high schools completed a self-administered questionnaire including demographic information, sleep/wake patterns, subjective insufficient sleep, excessive daytime sleepiness, irritability and sleep-promoting behaviors. We defined sleep debt as“the cumulative hours of sleep loss with respect to a subject-specific daily need for sleep”, and calculated it using the following equation: weekend sleep duration minus. weekday sleep duration. We then classified the students into two-groups based on a weighted mean（100min）of the discrepancy of sleep duration between weekday and weekend those with or without sleep debt of ≥100min
Results: Students with the sleep debt went to bed 24min later on weekday, and slept 28min shorter on weekday than those without the sleep debt, but there was no significant difference in weekday wake-up times between the two groups. Contrary to weekday, students with the sleep debt went to 29min later, woke up 129 min later and slept 107min longer on weekends than those without the sleep debt. Furthermore, prevalence of insufficient sleep（70.7% vs. 54.2%）, excessive daytime sleepiness（49.5% vs. 41.5%）, irritability（29.6% vs. 24.7%）, breakfast skipping（19.5% vs. 12.5%）and nodding off during the day（71.6% vs. 60.4%）was observed more frequently in students with the sleep debt than in those without the sleep debt. Logistic analyses with a generalized linear mixed model revealed that practice of 12 sleep-promoting behaviors, such as getting up at a fixed time every morning（OR=0.81, 95% CI: 0.66-0.99）, exposing oneself to sunlight in the morning（OR=0.76, 95% CI: 0.64-0.89）, and not going out to brightly-lit places, such as convenience stores, after 9：00 pm（OR=0.70, 95% CI: 0.53-0.93）, were associated with a lower odds ratio of having the sleep debt, late bedtime or insufficient sleep.
Conclusion: Late bedtimes, less weekday and longer weekend sleep durations, and late weekend wake-up time were observed in students with the sleep debt. Our results suggest that 12 sleep-promoting behaviors, all of which are items contributing to advance bedtime and/or to ensure sleep duration, play an important role in alleviating the sleep debt, late bedtime and insufficient sleep in high school students. We hope that this sleep-promoting behavior menu is utilized as a sleep support for students with similar sleep problems.
