INTRODUCTION Motor vehicle crashes (MVC) are the second leading cause of death for adolescents in the United States, with drowsy driving a major contributing factor. Early school start times have been identified as a significant factor that reduces adolescent sleep duration, which in turn contributes to drowsy driving and MVC. This paper examined the longitudinal impact of delaying secondary school start times on self-reported student drowsy driving and teen MVC. METHODS Secondary school students (10th and 11th grade, 51.7% female, 67.8% White) in the United States completed annual surveys 1 year before and 2 years after implementation of later school start times (70-min delay, n range 1642-2452 per year), reporting frequency of drowsy driving (less than once/week vs. at least once/week). Teen (16-18 years) MVC data from the Colorado Department of Transportation for the 2 years before and 2 years after later start time implementation were compared for Arapahoe County (where start times changed) and neighboring Adams County and Douglas County (where start times did not change). RESULTS With later start times, there was a significant drop in the percent of students who reported frequent drowsy driving (pre-change: 32.6%, post-change: 21.9%, follow-up: 22.8%). Weekday teen MVC rates went down in Arapahoe County (p = .04) during the school year, while no change or increases in MVC rates were seen in neighboring counties. CONCLUSIONS Healthy school start times are important for adolescent health and safety, with study findings highlighting the downstream effects of increased sleep duration following a 70-min delay in secondary school start times on adolescent drowsy driving and teen MVC rates.

中文翻译：

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昏昏欲睡的驾驶和青少年机动车撞车事故：改变上学时间的影响。

引言 机动车碰撞 (MVC) 是美国青少年死亡的第二大原因，而疲劳驾驶是一个主要因素。早期上学时间已被确定为减少青少年睡眠时间的重要因素，这反过来又会导致昏昏欲睡的驾驶和 MVC。本文研究了推迟中学开学时间对自我报告的学生昏昏欲睡和青少年 MVC 的纵向影响。方法 美国中学生（10 年级和 11 年级，女性占 51.7%，白人占 67.8%）在实施延迟开学时间前 1 年和实施后 2 年完成年度调查（延迟 70 分钟，n 范围 1642-2452 每年），报告疲劳驾驶的频率（每周少于一次与每周至少一次）。科罗拉多州交通部的青少年（16-18 岁）MVC 数据在开始时间实施之前的 2 年和之后的 2 年中比较了阿拉帕霍县（开始时间发生变化）和邻近的亚当斯县和道格拉斯县（开始时间没有改变）。结果 随着开始时间较晚，报告经常疲劳驾驶的学生百分比显着下降（更改前：32.6%，更改后：21.9%，后续：22.8%）。在学年期间，阿拉帕霍县的工作日青少年 MVC 率下降 (p = .04)，而邻近县的 MVC 率没有变化或增加。结论 健康的上学时间对青少年的健康和安全很重要，