Objective: To investigate the relationship between classroom lighting and poor vision of students in primary and secondary schools in Tianjin, and to provide reference for targeted prevention measures for comprehensive school eye health programmes. Methods: A total of 623 classrooms and 24 713 students in 89 primary and secondary schools in Tianjin were selected using stratified cluster sampling method in Sep.to Oct. of 2020. The illuminometer was used to monitor the lighting environment of the classroom, and the standard logarithmic vision light box was used to detect the naked eye vision of students. Chisquare test, variance analysis and binary Logistic regression were used in SPSS software. Results: Rate of low vision among primary and secondary school students in Tianjin was 67.86%. The qualification rate of blackboard reflectance, blackboard average illumination, blackboard illumination uniformity, desk average illumination and desk illumination uniformity were 58.11%, 53.13%, 73.19%, 66.61% and 75.12%, respectively. Univariate analyses showed that the blackboard reflectance, blackboard average illumination, desk average illumination, and desk illumination uniformity were associated with low vision among students(χ 2=311.29, 62.54, 61.71, 6.59, P<0.05). Multivariable Logistic regression analysis showed that blackboard reflectance, average illumination of blackboard and desk were associated with higher risk of poor vision[OR(95%CI)=1.19(1.11-1.27),1.27(1.17-1.37),1.11(1.02-1.20), P<0.05]. Conclusion Prevalence of low vision among primary and secondary school students in Tianjin is relatively high. Blackboard reflectance, average illumination of blackboard and desk are the important determinants for poor vision of primary and secondary school students. Creating effective classroom lighting scheme is crucial for vision health among students.

Objective: To investigate the relationship between physical activity, sleep duration, overweight, obesity and depressive symptoms among middle school students in Tianjin, and to provide the evidence for targeted prevention of depression. Methods: In September 2019 to 2021, the stratified cluster sampling method was used to select 52 747 middle school students from 16 districts in Tianjin for questionnaire survey, including demographics, depressive symptom, sleep status and physical activity. The χ 2 test and multivariate Logistic regression were used to analyze the data. Results: The prevalence of depressive symptoms among middle school students in Tianjin was 19.07%, with higher prevalence in female, urban areas, resident students and left behind students ( χ 2=128.44, 155.77, 35.29, 19.15, P <0.05). The prevalence of overweight and obesity were 20.64% and 22.13%, the proportion of students who met physical activity, outdoor activity, sleep duration guideline were 49.54%, 33.64%, 25.77%, respectively. Logistic regression results showed that meeting the guidelines on physical activity, outdoor activity, sleep duration and BMI were negatively correlated with depression symptoms, with sleep duration showed the highest protective effects on depressive symptoms( OR=0.60, 95%CI =0.57-0.63, P <0.05). Compared with students who did not meet any guidelines, students who met 4 guidelines had a lower risk of depression symptoms( OR=0.39, 95%CI =0.34-0.46, P <0.05). Conclusion The prevalence of depressive symptoms of middle school students in Tianjin is in moderate level, and the intervention should be comprehensively administered in terms of sleep duration, physical activity, outdoor activities, as well as overweight and obesity to reduce the occurrence of depression symptoms among middle school students.

Objective: To understand the prevalence and influencing factors of scoliosis among middle school students in Tianjin, and to provide scientific basis for the prevention and treatment of scoliosis. Methods: Based on stratified cluster random sampling method, 21 679 middle school students from 62 middle schools (35 middle schools and 27 high schools) in Tianjin were selected for scoliosis screening and completed relevant questionnaires. Results: The prevalence of scoliosis in middle school students in Tianjin was 4.00%, with girls (5.13%) higher than that in boys (2.94%), vocational high school (5.96%) higher than that in ordinary senior high school (4.98%) and junior high school (3.00%), the differences were statistically significant ( χ 2=67.56, 71.46 , P <0.01). Multivariate Logistic regression showed that gender, district, school segment, number of physical educaiotn(PE) classes per week, outdoor activity time per day, and days of 60 minutes or more of moderate and vigorous exercise per day in a week were related to the detection rate of scoliosis( OR=0.12-1.95, P <0.05). Conclusion The detection rate of scoliosis among middle school students in Tianjin varies in gender, resident area and school level, so more attention should be paid to girls, high school students and students in middle economic area. Comprehensive efforts should incorporate duration, intensity and type of physical exercise.

Objective To investigate the status and the relationship between obesity and high blood pressure in children and adolescents in Tianjin, and to provide a reference for the development of targeted prevention and control measures for high blood pressure in children and adolescents. Methods In September 2019, a stratified cluster sampling method was used to select 30 403 children and adolescents aged 7-17 from 94 primary and secondary schools in 16 districts in Tianjin. Height, weight and blood pressure were measured by standard methods. SPSS 24.0 was used for χ² test, variance analysis and binary logistic regression. Results The detection rate of overweight in children and adolescents in Tianjin was 17.28%, including 19.32% in boys and 15.07% in girls. The detection rate of obesity in children and adolescents in Tianjin was 22.79%, including 27.20% in boys and 18.01% in girls. The detection rate of high blood pressure in children and adolescents in Tianjin was 20.88%, including 20.98% in boys and 20.77% in girls. The detection rates of high blood pressure in the normal BMI group, overweight group and obesity group were 14.03%, 23.41% and 36.95%, respectively, and the difference was statistically significant (P<0.001). Compared to the normal BMI group, overweight and obesity were risk factors for high blood pressure in children and adolescents (OR=1.872, 95% CI:1.735~2.021; OR=3.598, 95% CI:3.366~3.827). Conclusion Overweight and obesity were important influencing factors for high blood pressure in children and adolescents aged 7-17 years. Controlling overweight and obesity is an important means to effectively cope with high blood pressure.

Objective To investigate the prevalence and risk factors of depression among middle school students in Tianjin , and to provide the evidence for making targeted prevention of depression. Methods In September 2019 and September 2020, the stratified cluster sampling method was used to select 32 380 middle school students in Tianjin for face-to-face questionnaire survey, which included the basic information , depressive symptoms , health status , life and behavior habits , injuries , and Internet addiction in the previous week. The χ² test , t test, univariate and multivariate logistic stepwise regression were used to analyze the data. Results From 2019 to 2020, the prevalence of depression among middle school students in Tianjin was 20.48% , with higher prevalence in girls than in boys and higher prevalence in urban areas than in suburban areas. Multivariate regression results show that smoking, school bullying, parental abuse, Internet addiction , injury , urban area , female , sickness, anemia and sweets are risk factors for depression ; fruits , vegetables , breakfast , high Intensive exercise are protective factors. The OR ( 95%CI ) of depression of school bullying and parental beating and scolding were 4.71 ( 95%CI 3.84 -5.79) and 2.94 ( 95%CI 2.72 - 3.18); the OR ( 95%CI ) of depression of internet addiction students was 2.76 ( 95%CI 2.30 - 3.11); the OR ( 95%CI ) of depression in anemia students was 1.68 ( 95%CI 1.36 - 2.07); compared with non-smokers, the odd ratio(OR) ( 95%CI ) of depression for smoking less than 1 cigarette, 1-11 cigarette, and 11-20 cigarette per day were 1.83 ( 95%CI 0.75 - 2.44), 1.64 ( 95%CI 0.94 -2.84 ), 1.92 ( 95%CI 1.51 - 2.44), respectively; Conclusion The depression level of middle school students in Tianjin is in the middle, and the intervention should be interfered from many aspects, such as cultivating students' good living behavior habits and healthy body, providing good family atmosphere and campus environment.