Abstract
Backgrounds: Sleepiness is reported to predict sleep quality, academic performance and self-regulation. This study aimed to discover determinants of sleepiness. Methods: On 2722 questionnaires obtained from pupils in grades 5 - 12 in the Kanto district of Japan, lifestyle habits associated with sleepiness were analyzed using a multivariable logistic regression model. Results: The rate of sleepy pupils (who feel sleepy during class as often and always) increased from elementary school (6.3%) to senior high school (42.4%) via junior high school (17.1%). Higher grade (adjusted odds ratio [OR], 1.28; 95% confidence interval [CI], 1.21 - 1.37; p Conclusions: To reduce adolescents’ sleepiness in the Kanto district of Japan, we recommend them to have adequate waking time, and to avoid late bedtime, breakfast skipping, excessive screen time, after-school activity, and physical activity. Further prospective studies are needed to confirm involvements of these recommended factors in sleepiness and both physical and mental health outcomes.