Sleep Patterns Middle and High School Students in Seoul

Song, H S; Park, Y M; Nam, M; Kim, L

Abstract

OBJECTIVES
It is been reported that sleep patterns change significantly during the adolescent years. In Korea, the sleep patterns of adolescents have not been investigated systematically. The authors performed preliminary study about sleep patterns of middle and high school students in Seoul before nationwide study.
METHODS
The authors selected one of middle and high schools located in typical middle class area in Seoul. The study was performed during the periods when examination or vacation did not affect the sleep cycle. Fifty to one hundred male and female students were selected from one school year each. One of investigators explained the purposes and methods of this study to the students and gave additional explanation to the teachers in charge. We designed a questionnaire for subjects to describe the nap time, bedtime, sleep latency, total sleep time, rise time and sleep efficiency, and the students recorded sleep logs for seven days including weekend. Eight hundred three students answered the questionnaires. Among them, we selected the subjects who recorded sleep logs at least three days and filled up the questionnaires completely. Finally, seven hundred seventy one subjects were included in this study. Weekend was defined as the time from Saturday morning to Sunday morning, and Sunday sleep patterns were treated separately.
RESULTS
Across the six school years, school-night bedtimes were delayed one hundred twenty four minutes and school-night rise times were advanced by thirty five minutes. School-night total sleep times were decreased by one hundred fifty eight minutes, and weekend bedtimes were delayed by one hundred twenty five minutes. The students tended to oversleep on weekends, and the mean of weekend oversleep was ninety six minutes. But, bedtime in weekends was not delayed. Daytime sleep, sleep latency and sleep latency and sleep efficiency were not changed greatly across six school years. Total sleep time of female students was decreased significantly between third middle school year and first high school year, but time of male students was decreased between first and second high school year.
CONCLUSION
It is supposed that sleep deficiency of middle and high school students in Seoul was due to delayed bedtimes and advanced rise times across the school years.