Departments of *Psychiatry and Human Behavior and †Pediatrics, Alpert Medical School of Brown University, Providence, RI; ‡Bradley-Hasbro Children's Research Center, Rhode Island Hospital, Providence, RI; §Division of Pulmonary and Sleep Medicine, Children's National Medical Center, Washington, DC; ‖Department of Pediatrics, School of Medicine and Health Sciences, George Washington University, Washington, DC.
J Dev Behav Pediatr. 2014 Jan;35(1):11-7. doi: 10.1097/DBP.0000000000000018.
Chronic insufficient sleep is a growing concern among adolescents and is associated with a host of adverse health consequences. Early school start times may be an environmental contributor to this problem. The purpose of this study was to examine the impact of a delay in school start time on sleep patterns, sleepiness, mood, and health-related outcomes.
Boarding students (n = 197, mean age = 15.6 yr) attending an independent high school completed the School Sleep Habits Survey before and after the school start time was experimentally delayed from 8:00 a.m. to 8:25 a.m.
The delay in school start time was associated with a significant (29 min) increase in sleep duration on school nights. The percentage of students receiving 8 or more hours of sleep on a school night increased to more than double, from 18% to 44%. Students in 9th and 10th grade and those with lower baseline sleep amounts were more likely to report improvements in sleep duration after the schedule change. Daytime sleepiness, depressed mood, and caffeine use were all significantly reduced after the delay in school start time. Sleep duration reverted to baseline levels when the original (earlier) school start time was reinstituted.
A modest (25 min) delay in school start time was associated with significant improvements in sleep duration, daytime sleepiness, mood, and caffeine use. These findings have important implications for public policy and add to research suggesting the health benefits of modifying school schedules to more closely align with adolescents' circadian rhythms and sleep needs.
青少年慢性睡眠不足是一个日益受到关注的问题，它与许多不良健康后果有关。上学时间过早可能是造成这一问题的环境因素之一。本研究旨在探讨推迟上学时间对睡眠模式、嗜睡、情绪和与健康相关的结果的影响。
参加一所独立高中的寄宿学生（n=197，平均年龄=15.6 岁）在学校开始时间从早上 8:00 实验性推迟到 8:25 之后，填写了学校睡眠习惯调查问卷。
上学时间推迟与睡眠时间显著增加（29 分钟）相关。在上学日获得 8 小时或更多睡眠时间的学生比例从 18%增加到 44%，增加了一倍多。9 年级和 10 年级的学生以及基线睡眠时间较低的学生在作息时间改变后更有可能报告睡眠时间延长。白天嗜睡、抑郁情绪和咖啡因使用均显著减少。当恢复到原来（更早）的上学时间时，睡眠时间恢复到基线水平。
上学时间适度推迟（25 分钟）与睡眠时间、白天嗜睡、情绪和咖啡因使用显著增加有关。这些发现对公共政策具有重要意义，并进一步证明了调整学校作息时间以更符合青少年的生物钟和睡眠需求的健康益处。
