School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.
Chinese Center for Disease Control and Prevention, National Institute for Nutrition and Health, Beijing, China.
J Expo Sci Environ Epidemiol. 2022 Mar;32(2):223-231. doi: 10.1038/s41370-021-00401-w. Epub 2022 Jan 4.
The outdoor time is a key factor that determines children's exposure to environmental contaminants. Meanwhile, children reap numerous physical and mental health benefits from playing outdoors.
This study aimed to characterize the distributions and identify determinants of the time spent outdoors among school-age children in China.
The study recruited 41,439 children aged 6-17 years in Mainland China using a multi-stage cluster random sampling method. This sample was nationally representative with sample weights created to account for the complex survey design. Information on time-activity patterns were collected with a standard questionnaire through face-to-face interviews. Frequency distributions of time outdoors were created by age group, gender, region, and other sociodemographic factors with sample weights. The key factors influencing time outdoors were identified using multivariable linear regression models.
The grand mean (±standard deviation) time outdoors was 101 ± 51 min/day for all the study participants, 22.3% having <60 min/day. Children spent longer time outdoors in warm seasons and on weekends. Children's outdoor time was significantly influenced by gender, age, urbanicity, region, annual total household expenditure, building environment, and meteorological conditions (annual mean temperature, sunshine time, and precipitation). Girls, 15-17 year old, and urban children had 6 min/day, 8 min/day, and 13 min/day less outdoor time than boys, 6-8 year old, and rural children, respectively. Most significantly, urban girls and high school students had the shortest outdoor time. The cement ground was the most important type of ground for children playing outside.
This was the first national-scale study that characterized the time outdoors and where is it spent among school-age children in China. It revealed that one-fifth of Chinese children spent less than one hour outdoors every day, and urban girls had particular "indoor tendencies". The findings provide bases for future interventions and guidelines aimed at promoting children's physical activities.
户外活动时间是决定儿童接触环境污染物的关键因素。同时，儿童从户外活动中获得许多身心健康益处。
本研究旨在描述中国学龄儿童户外活动时间的分布情况，并确定其影响因素。
本研究采用多阶段整群随机抽样方法，在中国内地招募了 41439 名 6-17 岁的儿童。该样本具有全国代表性，并创建了样本权重，以考虑到复杂的调查设计。通过面对面访谈，使用标准问卷收集时间活动模式信息。根据年龄组、性别、地区和其他社会人口因素以及样本权重，创建户外活动时间的频数分布。使用多变量线性回归模型确定影响户外活动时间的关键因素。
所有研究参与者的户外活动时间平均值（±标准差）为 101±51 分钟/天，22.3%的儿童户外活动时间<60 分钟/天。儿童在温暖季节和周末的户外活动时间较长。儿童户外活动时间受性别、年龄、城市、地区、家庭总支出、建筑环境和气象条件（年平均气温、日照时间和降水量）显著影响。女孩、15-17 岁和城市儿童的户外活动时间比男孩、6-8 岁和农村儿童分别少 6 分钟/天、8 分钟/天和 13 分钟/天。最显著的是，城市女孩和高中生的户外活动时间最短。水泥地是儿童户外活动的最重要地面类型。
这是第一项描述中国学龄儿童户外活动时间及其活动地点的全国性研究。研究结果表明，五分之一的中国儿童每天户外活动时间不足一小时，城市女孩尤其有“室内倾向”。研究结果为未来旨在促进儿童身体活动的干预措施和指南提供了依据。
