Objective: To investigate the sleep characteristics of children aged 3-12 years old in Shanghai, and to provide a reference for improving pediatric sleep health. Methods: From April to June 2019, 16 542 children aged 3-12 years old were randomly selected from 31 kindergartens and 17 primary schods in Shanghai, and a cross sectional epidemiological survey was conducted using multi stage cluster sampling. The Children s Sleep Habits Questionnaire (CSHQ) was used to evaluate sleep characteristics. Results: The bedtime routine of children in Shanghai was (21:27±00:36) and (21:46±00:46) on weekdays and weekends, respectively. Corresponding wake up times were (6:52±00:28) and (7:47±00:48), total sleep duration was (9.05±1.07) and (9.52±1.17)h, and the prevalence of inadequate sleep was 81.0% and 55.4%. The average score of sleep problems was (51.56±8.04), and the prevalence of disturbed sleep was 93.5%. With advancing age, the total sleep time of children in Shanghai decreased, and the difference in weekend weekday sleep patterns increased. Furthermore, two major sleep problems were observed, namely, short sleep duration and daytime sleepiness, which became increasingly more prominent. Girls usually went to bed later on weekdays and woke up later on weekends, and a greater difference in weekend weekday sleep patterns was observed. Moreover, psychological problems such as sleep anxiety were more serious among girls. Conclusion At present, children in Shanghai have insufficient sleep time and late bedtimes. Large differences in weekend weekday sleep patterns were observed, and various sleep problems were identified. Sleep related anxiety and differences in weekend weekday sleep patterns were particularly high among girls.

Objective: To examine the prevalence of allergic diseases in schoolaged children from Shanghai and to explore related factors so as to produce epidemiological data regarding allergic diseases in children. Methods: Multistage cluster sampling was used to carry out the study in Shanghai from April to June 2019. A total of 10 686 children aged 7-12 years from 17 primary schools participated in the survey. The International Study of Asthma and Allergies in Childhood (ISAAC)Scale was used to evaluate allergic diseases. Multivariate Logistic regression analysis was performed to analyze the related factors. Results: The overall prevalence of allergic diseases among schoolaged children in Shanghai was 47.0%. A higher prevalence was observed among boys (50.4% vs 43.3% in girls, χ2=54.44, P<0.01). Common allergic diseases included asthma (13.9%), allergic rhinitis (18.2%), and atopic dermatitis (34.3%). The Logistic regression analysis showed that the common risk factors of asthma, allergic rhinitis and atopic dermatitis included the following:male gender (OR=1.52,1.44,1.22); mother has a bachelors degree or above (OR=1.26,1.77,1.84); family history of allergic diseases (OR=2.87,4.24,2.57); only child (OR=1.16,1.28,1.22); curtain cleaning frequency <1 time/month (OR=1.41,1.79,1.77); room not cleaned daily (OR=1.14,1.18,1.20); and dust exposure frequency ≥1 time/month (OR=1.45,1.56,1.42), all P<0.05. These three types of allergic diseases were also associated with unique risk factors that dependent on socialenvironmentalbehavioral factors. Conclusion Compared with previous data, the prevalence of allergic diseases among schoolaged children in Shanghai increased significantly in 2019. The related influencing factors involve multiple variables including demographics, environmental exposure and behavior, which warrant further exploration.

Objective: To explore the association between exclusive breastfeeding and sleep onset delay among school aged children, and to provide a reference for promoting childhood sleep health. Methods: A total of 10 686 children aged 7-12 years old were recruited from 17 primary schools in Shanghai using the multi stage sampling method from April to June 2019. The duration of sleep onset delay and exclusive breastfeeding were identified using the Children s Sleep Habits Questionnaire and a self designed questionnaire, respectively. The association between the duration of exclusive breastfeeding and the score and the risk of sleep onset delay were estimated using linear regression and a Logistic regression model, respectively. Results: After adjusting for confounding factors, compared with never exclusive breastfeeding, the score of sleep onset delay decreased by 0.07, 0.08 and 0.05 in cases that involved exclusive breastfeeding for less than 3 months, 3-6 months and more than 6 months, respectively; and the odds of sleep onset delay decreased by 39.0%(OR=0.61, 95%CI=0.47-0.79), 41.1%(OR=0.59, 95%CI=0.47-0.75) and 21.1%(OR=0.79, 95%CI=0.65-0.96), respectively. Similar findings were observed in analyses stratified by gender, although the association was stronger among boys. Moreover, administration of probiotics or yogurt only improved sleep onset delay in those who were exclusively breastfed for no more than 6 months. Conclusion Longer durations of exclusive breastfeeding were associated with a lower risk of sleep onset delay among school aged children. However, exclusive breastfeeding for over 6 months diminished the protective effect that was otherwise observed on sleep onset delay.