Background: It is known that short sleep duration adversely affects children's behavior and physical development. This study aimed to investigate the status of sleep duration in 3-14-year-old children in Beijing and explore the related factors of sleep loss with them.
Methods: In this study, a cross-sectional study of random stratified cluster sampling was conducted on 3-14-year-old children and adolescents in Beijing. According to the proportion of children in each district and school, the final cohort included a total of 11 kindergartens, 7 primary schools, and 8 junior high schools from 7 districts of Beijing. Children of sampled classes were included, and their parents were invited to fill a series of questionnaires including the simplified Chinese version of Pediatric Sleep Questionnaire, Sleep Questionnaire Scale, and Hong Kong-Children Sleep Questionnaire about the performance of the last 6 months.
Results: Out of the total 11,420 questionnaires, 9198 questionnaires were valid and effective with the response rate of 80.54%. The age of the investigated children was 8.8 ± 3.8 years, including 4736 males and 4462 females. The daily sleep duration of children in Beijing was 9.7 ± 0.7 h. The prevalence of sleep loss (<9 h/day) of children in Beijing was 11.8%. The daily sleep duration of children aged <6, 6 ≤ age <11, and ≥11 years was 9.7 ± 0.6 h, 9.6 ± 0.6 h, and 9.5 ± 0.8 h, respectively. The sleep duration reduced significantly in children aged ≥11 years as compared to younger children in Beijing which was mainly contributed by the variation tendency of sleep duration on weekdays. The multivariate logistic regression analysis identified factors associated with sleep loss (P < 0.05): male (odds ratio [OR] = 1.32, 95% confidence interval [CI]: 1.15-1.51), age ≥11 years (OR = 2.37, 95% CI: 1.92-2.93), overweight (OR = 1.34, 95% CI: 1.17-1.54), family history of snoring (OR = 1.35, 95% CI: 1.13-1.61) and activities before bedtime with watching TV (OR = 1.24, 95% CI: 1.08-1.43), sports (OR = 1.22, 95% CI: 1.01-1.48), playing cellphone (OR = 1.91, 95% CI: 1.31-2.73) and surfing the Internet (OR = 1.27, 95% CI: 1.06-1.52) and among them age ≥11 years and playing cellphone before bedtime had greater impact on children's short sleep duration than that of other factors.
Conclusions: Sleep loss was common among 3-14-year-old children in Beijing. Sleep duration decreased with age, especially among children over 11 years old. Factors associated with sleep loss covered sociodemographic characteristics, family sleep habits and routine activities before bedtime, and among those variables, age ≥11 years and playing with cellphones before bedtime had a greater impact on sleep duration, indicating that existing sleep loss in 3-14-year-old children could be, at least partly, improved by paying more attention to children aged of 11 years or entering Grade 5 and Grade 6 and to children with a family history of snoring; by reducing the use of electronic products before bedtime, especially cellphones; by managing weight and keeping fit; and by improving the bedtime routine.
北京市3-14岁儿童睡眠时间及其影响因素的横断面研究摘要背景: 睡眠不足会对儿童的行为和身体发育产生不利影响，本研究通过对北京市儿童睡眠时间的横断面调查，了解3-14岁儿童睡眠时间现状及相关影响因素。 方法: 通过随机分层整群抽样的横断面研究调查北京市3-14岁儿童及青少年。根据各区、各学校儿童及青少年人数所占比例制定抽样计划，共有来自北京市四大功能区的七个区县（西城区、朝阳区、门头沟区、房山区、昌平区、顺义区、怀柔区）的11所幼儿园，7所小学和8所初中参与调查。本研究最终以班级作为整群纳入被调查儿童，并邀请其父母就儿童近半年睡眠情况，完成系列问卷包括简体中文版儿童睡眠问卷（PSQ）、睡眠问卷调查表和香港儿童睡眠问卷（HK-CSQ）。 结果: 本研究共发放问卷11,420份，其中有效数据9198条（有效应答率80.54%）。调查儿童年龄为8.8±3.8岁，其中男性4736人，女性4462人。全市3-14岁儿童的每日睡眠时间为9.7±0.7小时，睡眠不足（每日睡眠＜9小时）阳性率为11.8%；其中＜6岁，6-11岁以及≥11岁儿童的每日睡眠时间分别为9.7±0.6小时，9.6±0.6小时和9.5±0.8小时，≥11岁儿童睡眠时间随年龄的增长而下降的趋势较小年龄组明显，相似的下降趋势在工作日睡眠时间中更为突出。经过多元回归分析，与睡眠不足显著相关(P<0.05)的因素包括：男性(OR=1.32, 95% CI: 1.15-1.51),年龄≥11岁(OR=2.37, 95% CI: 1.92-2.93),超重(OR=1.34, 95% CI: 1.17-1.54),家庭打鼾史(OR=1.35, 95% CI: 1.13-1.61)， 睡前看电视(OR=1.24, 95% CI: 1.08-1.43),睡前运动(OR=1.22, 95% CI: 1.01-1.48),睡前玩手机(OR=1.91, 95% CI: 1.31-2.73)和睡前上网(OR=1.27, 95% CI: 1.06-1.52)；其中年龄≥11岁和睡前玩手机对儿童睡眠不足的影响更大。 结论: 睡眠不足在北京市3-14岁儿童中是普遍存在的。睡眠时间随着年龄的增长而呈下降趋势，尤其对于11岁及以上儿童而言，下降趋势更加明显。本研究所纳入的睡眠不足相关影响因素包括社会人口学特征、家庭睡眠习惯和睡前日常活动，其中年龄≥11岁和睡前玩手机对睡眠不足的影响更大。本研究重要的临床意义在于提示我们，11岁或者五、六年级以上的儿童及有家庭打鼾史的儿童的睡眠需要更多关注，另外通过减少睡前电子产品的使用，特别是玩手机的频率和时间，管理体重和优化睡前生活习惯是对儿童睡眠不足进行干预或预防的有效措施。基于本研究的结论，我们呼吁家庭与学校一起努力，为预防和缓解儿童睡眠不足做出科学的努力。.
Keywords: Child; Cross-Sectional Survey; Sleep Duration.