卫生研究

目的 分析2015年和2019年北京市6～14岁学生视屏时间的特征及其变化情况。方法 采用多阶段整群抽样方法，使用北京市疾病预防控制中心编制的《营养与健康状况调查问卷》于2015年、2019年对北京市7个区的一、三、五年级及初一年级学生课余视屏时间进行调查。2015年调查4152名学生，2019年调查4202名。采用Mann-Whitney U检验、χ²检验分析不同人口学特征调查对象日均视屏时间(以四分位数表示)和超标率[以n(r/%)表示]的差异情况；采用广义线性混合模型，分析不同年份、性别、年龄、城郊与视屏时间是否超标的关联。结果 2015年调查对象视屏时间为54(31,84)min/d, 2019年为41(26,69)min/d(P<0.01);2015年调查对象日均视屏时间超标率(≥2 h/d)为10.06%(403/4005),2019年为5.01%(203/4052)(P<0.01)。与2015年相比，2019年不同性别(男性：Z=-6.95,Z=-9.37,Z=-9.55;女性：Z=-4.63,Z=-10.77,Z=-8.94)、年龄(6～9岁：Z=-4.12;Z=-8.38;Z=-7.06;10～14岁：Z=-7.63;Z=-11.89;Z=-11.63)、城郊(城区：Z=-5.37;Z=-10.48;Z=-9.11;郊区：Z=-6.13;Z=-10.02;Z=-9.62)日均视屏时间(上学日、周末、一周)均下降(P<0.01)。广义线性混合模型分析显示，2019年调查对象日均视屏时间超标率低于2015年(β=-0.74,OR=0.48,95%CI 0.40～0.57);与其他同类特征组相比，男性(β=0.26,OR=1.29,95%CI 1.09～1.53)、10～14岁(β=0.67,OR=1.95,95%CI 1.64～2.32)、居住在郊区(β=0.57,OR=1.77,95%CI 1.47～2.12)的调查对象视屏时间超标率更高(P<0.01)。结论 2019年北京市6～14岁学生的日均视屏时间与超标率较2015年整体显著下降。但男性、10～14岁及居住在郊区的学生视屏时间与超标率始终高于同类别其他群体。

OBJECTIVE To analyze the characteristics and changes in screen time among students aged 6-14 years in Beijing in 2015 and 2019.METHODS A multistage cluster sampling approach was adopted. A survey on after-school screen time was conducted among students in grades 1, 3, 5, and 7(first year of junior high school) in 7 districts of Beijing in 2015 and 2019, using the Nutrition and Health Status Questionnaire developed by the Beijing Center for Disease Prevention and Control. A total of 4152 primary and secondary school students were surveyed in 2015, and 4202 in 2019. The Mann-Whitney U test and chi-square test were employed to analyze differences in daily average screen time and the prevalence of exceeding the daily screen time limit among respondents with different demographic characteristics. Using a generalized linear mixed model(GLMMs) to analyze the association between different years, gender, age, residential areas, and whether screen time exceeds the limit.RESULTS Survey result showed that the median screen time of respondents was 54(31,84) min/d in 2015 and 41(26,69) min/d in 2019, representing a decrease of 13 min/d(P<0.01). The prevalence of exceeding the daily screen time limit(≥2 h/d) was 10.06%(403/4005) in 2015 and 5.01%(203/4052) in 2019, a reduction of 5.05 percentage points(P<0.01). Compared with 2015, the daily average screen time(school days, weekends, and the entire week) of respondents across different genders, age groups, and regions all decreased in 2019(male: Z=-6.95,Z=-9.37,Z=-9.55;female: Z=-4.63,Z=-10.77,Z=-8.94;6-9 years: Z=-4.12,Z=-8.38,Z=-7.06;10-14 years: Z=-7.63,Z=-11.89,Z=-11.63;urban: Z=-5.37,Z=-10.48,Z=-9.11;suburban: Z=-6.13,Z=-10.02,Z=-9.62;P <0.01). GLMMs analysis revealed that the daily average screen time exceeding rate among survey subjects in 2019 was lower than in 2015(β =-0.74, OR=0.48,95% CI 0.40-0.57). Compared with their counterparts with the same characteristics, respondents who were male(β = 0.26, OR=1.29, 95%CI 1.09-1.53), aged 10-14 years(β=0.67,OR=1.95,95%CI 1.64-2.32), and residing in suburban areas(β=0.57, OR=1.77, 95%CI 1.47-2.12) had a significantly higher rates of excessive screen time(P<0.01).CONCLUSION The daily average screen time and prevalence of excessive screen time among primary and secondary school students in Beijing decreased significantly overall in 2019 compared with 2015. However, male students, age 10-14 years, and those residing in suburban areas consistently had higher screen time and a higher prevalence of excessive screen time than their counterparts within the same categories.