Objective: To describe the prevalence and relationship between moderate to vigorous physical activity(MVPA), screen time (ST) and depressive symptoms among middle school students in Guangzhou, and to provide a reference for adolescent depression prevention and control. Methods: Using stratified cluster random sampling method, a total of 2 140 students were selected from one urban area and one suburban country for MVPA, ST and depressive symptoms investigation. Logistic regression was used to analyze relations among MVPA, ST and their combined patterns for depressive symptoms. Results: A total of 89.72% students failed to meet the MVPA recommendations, girls (95.52%) were higher than boys(84.38%). Totally 67.38% of the students failed to meet the ST recommendations, boys (69.75%) were higher than girls(64.81%). The prevalence of depressive symptoms was 27.01%, girls (31.58%) higher than boys(22.80%). MVPA, ST failure compliance rate and depression symptoms detection rate of vocational high school and ordinary high school were higher than junior high school ( χ 2=6.40,121.71,27.37, P ＜ 0.05 ). Logistic regression analysis showed that the OR for depressive symptoms was 1.19 ( P =0.35) in students whose MVPA time achieving 1 h<7 d in the last week, and was 1.93 ( P <0.01) in students with the ST>2 h/d independently, no significant interactions were observed. Students with both MVPA time 1 h<7 d in the last week and the ST>2 h/d were more likely to report depressive symptoms( OR=2.03, P <0.05). Conclusion Insufficient MVPA, prolonged ST and high prevalence of depressive symptoms are observed among middle school students in Guangzhou. Students with both insufficient MVPA and prolonged ST are more likely to suffer from depressive symptoms. Specific psychological care and health education regarding physical activity and screen behavior should be implemented to students with different characteristics, as well as their parents for depressive symptom prevention.

Objective: To understand the status and associated factors of knowledge, attitude and practice (KAP) about myopia prevention and control among young children s parents in Guangzhou, so as to provide reference for family health education on myopia prevention and control. Methods: During January to February 2023, 4 584 parents of children from kindergarten and primary school (grade 1-3) were recruited. Two to three kindergartens and 2 primary schools were selected from each of the 3 urban districts and 2 suburb districts of Guangzhou by stratified cluster random sampling method. Parents of children were administered with online questionnaire survey on KAP about myopia prevention and control. Descriptive analyses and multivariate Logistic regression models were used. Results: The proportion of parents reaching standard of KAP about myopia prevention and control was 61.54%, the knowledge awareness rate was 57.30%, the positive attitude holding rate was 76.98% and the health practice formation rate was 63.31 %. Internet (70.35%) and lectures on school health education/health education materials (66.14%) were the most common ways for obtaining knowledge for parents. Multivariate Logistic regression analysis showed that urban area, higher education ( college /undergraduate or above), annual household income 50 000-90 000, 100 000-290 000, 300 000-490 000, 500 000- 590 000 , and ≥600 000 Yuan, being aware of vision status (normal/poor) of their children, one or both parents with myopia, both parents with non myopia, acquiring knowledge by multi ways(2, 3, ≥4) were associated with higher KAP about myopia prev ention and control ( OR =1.23, 1.34, 1.36, 1.25，1.49, 1.93, 2.34, 1.64, 1.66, 1.89, 3.48, 3.09, 2.42, 1.65, 2.29, 3.22, P ＜ 0.05). Conclusion Knowledge and practice about myopia prevention and control among young children s parents in Guangzhou are insufficient, yet the attitude was satisfactory. It is necessary to carry out targeted education for parents, especially those living in suburb area, with low education and income level.