OBJECTIVE The purpose of this study is to examine how the sleep duration changes during adolescence across the seventh, eighth, ninth, and 10th grade periods, and to determine whether there is a difference between the cohorts. METHOD For these purposes, we used the latent growth curve modeling and the multi-group analysis involving 2081 students (2000-birth cohort data) and 2254 students (1997-birth cohort data) who participated in the Korean Children and Youth Panel Survey. The data were collected using a stratified multistage cluster sampling method. RESULTS Sleep duration became shorter as age increased. Furthermore, the sleep duration of the 2000-birth cohort became shorter than the sleep duration of the 1997-birth cohort. Specifically, the mean value of the initial sleep duration of the 2000-birth cohort was 8.09 h, which was significantly shorter than the initial value 8.36 h of the sleep duration of the 1997-birth cohort. In addition, multi-group analysis revealed that the trajectories of sleep duration and its predictors were varied by cohort. Specifically, parent supervision, peer relationship, and electronic media factors (smartphone overuse, time spent on using computer and playing games) explained the cohort effect. CONCLUSION These findings suggest that environmental factors such as increasing use of electronic media or pressure regarding higher education to adolescents could be associated with reduced sleep duration.

中文翻译：

---

与青少年睡眠时间减少相关的队列效应。

目的本研究的目的是研究青春期在七，八，九和十年级的睡眠时间如何变化，并确定这两个队列之间是否存在差异。方法为此，我们使用了潜伏增长曲线建模和多组分析，参与了2081名学生（2000年出生的队列数据）和2254名学生（1997年的出生队列数据）参加了韩国儿童和青少年小组调查。使用分层多级聚类抽样方法收集数据。结果随着年龄的增长，睡眠时间缩短。此外，2000年出生队列的睡眠时间比1997年出生队列的睡眠时间短。具体而言，2000年出生队列的初始睡眠时间的平均值为8.09小时，这比1997年出生队列的睡眠时间的初始值8.36小时明显短。此外，多组分析显示，睡眠时间的轨迹及其预测因子因队列而异。具体来说，父母的监督，同伴关系和电子媒体因素（智能手机过度使用，花在使用计算机和玩游戏上的时间）解释了同类群组的影响。结论这些发现表明，环境因素，例如电子媒体使用的增加或青少年接受高等教育的压力可能与睡眠时间减少有关。父母的监督，同伴关系和电子媒体因素（智能手机过度使用，花在使用计算机和玩游戏上的时间）解释了同类群组的影响。结论这些发现表明，环境因素，例如电子媒体使用的增加或青少年接受高等教育的压力可能与睡眠时间减少有关。父母的监督，同伴关系和电子媒体因素（智能手机过度使用，花在使用计算机和玩游戏上的时间）解释了同类群组的影响。结论这些发现表明，环境因素，例如电子媒体使用的增加或青少年接受高等教育的压力可能与睡眠时间减少有关。