New onset and natural remission of excessive daytime sleepiness and its correlates among high-school students

Excessive daytime sleepiness (EDS) is highly prevalent among high-school students, and preventative measures against it are essential for promotion of school health. With the aim of studying both the onset and amelioration of EDS and the factors that can predict these changes during the period at high school, we conducted a series of longitudinal surveys using self-administered questionnaires. Surveys of students from three private high schools in Tokyo were conducted three times in November of each year, starting in 2007, when the subjects were in the 10th grade, and ending in 2009, when they were in the 12th grade. Of 1198 eligible students, 865 (effective response rate, 72.75%: 472 boys, 393 girls) were included in the analysis. The Japanese version of the Epworth Sleepiness Scale was used to assess their level of EDS, which was defined as being present when the total score was >10. Among 489 individuals who did not have EDS in the 10th grade, the cumulative incidence rate was 32.7% (95%CI: 29.6-35.8%) over 2years. In addition, the natural remission rate among 376 individuals who reported having EDS in the 10th grade was 39.4% (95CI: 36.1-42.7%). From the results of logistic regression analysis, "having sleep disturbance" and "not doing light exercise or gymnastics as a sleep-promoting practice" were extracted as the factors that predict the onset of EDS, whereas "not taking a nap during the weekend" was extracted as the factor that predicts the natural remission of EDS.