[Research progress on the impacts of pregnancy and puerperium-related factors on refractive errors in children].

Refractive error is a common ophthalmic disease in children. It refers to the mismatch between the axial length and the refractive power that results in visual blur, which is usually driven by the interaction of genetic and environmental factors. The impacts of pregnancy and puerperium-related factors on refractive error in children have gradually gained attention. According to the different stages of pregnancy, this review summarizes the impacts of four aspects on refractive error in children, including lifestyle during pregnancy, complications and comorbidities during pregnancy, adverse pregnancy outcomes and other factors, which aims to provide perinatal healthcare clues for the prevention and control of refractive error in children, achieve prevention beforehand and reduce the public health burden of refractive error in children.

[Relationship between sleep status and occasional hypertension in preschool children in three provinces in the middle and lower reaches of the Yangtze River in China].

Objective: To understand the prevalence of occasional hypertension in preschool children in three provinces in the middle and lower reaches of the Yangtze River in China, and analyze the relationship between their sleep status and occasional hypertension. Methods: From October to November 2017, a total of 24 842 preschool children from 109 kindergartens in 11 cities in Hubei, Anhui and Jiangsu provinces were selected by intentional sampling method. A self-made questionnaire was used to collect basic information about the subjects, and the sleep status data was collected by the Children's Sleep Habits Questionnaire. Physical examinations were performed on the subjects, and height, weight and blood pressure were measured on-site. The difference in occasional hypertension detection rate among preschool children with different characteristics was compared, and the correlation between sleep status and occasional hypertension detection rate was analyzed by the multivariate logistic regression model. Results: The age of the subjects was (4.4±1.0) years, including 12 729 boys (51.2%). The prevalence of occasional hypertension was 31.8% (7 907/24 842). The prevalence of occasional hypertension among preschool children in three provinces of the middle and lower reaches of the Yangtze River was 31.8%. There were statistically significant differences in the detection rate of occasional hypertension among preschool children of different genders, age groups, family residence, family economic status and parents' education level (all P values<0.05). The detection rate of occasional hypertension in children with less than 10 hours of sleep was higher than those with sufficient sleep, and the difference was statistically significant (P<0.05). The results of multivariate logistic regression analysis showed that after adjusting for factors such as gender, age, family residence, family economic status, parental education level, parental smoking history, and physical constitution, the ORs (95%CI) for less than 10 hours of sleep, turning on the lights while sleeping, and poor sleep quality were 1.09 (1.03-1.15), 1.17 (1.07-1.28) and 1.04 (0.91-1.18), respectively, compared with the corresponding reference group. Conclusion: The detection rate of occasional hypertension is high in preschool children in the middle and lower reaches of the Yangtze River and there is a positive correlation between insufficient sleep and turning on the light when sleeping and occasional hypertension in preschool children.

[Longitudinal correlation between cell phone use and sleep quality in college students].

Objective: To investigate the current situation of cell phone use and sleep quality among college students, establish a sleep quality trajectory model and explore the influence of cell phone use on the sleep quality trajectory. Methods: Based on data from the College Student Behavior and Health Cohort Study 2019-2020, a latent class growth modeling was used to establish a sleep quality trajectory model among college students. The baseline influencing factors of sleep quality trajectories among college students were analyzed by χ2 test, and the effects of cell phone use on sleep quality trajectories were analyzed by binary logistic regression. Results: A total of 1 092 college students were included in the analysis. The detection rates of cell phone use and poor sleep quality were 24.5% and 13.3%. Latent class growth model identified two groups of sleep quality trend trajactories: an improved sleep quality group (86.0%) and a decreased sleep quality group (14.0%). The result of binary logistic regression showed that the cell phone use was a risk factor of sleep quality trajectories. Conclusion: The cell phone use during college period could increase the risk of poor sleep quality. Targeted intervention measures about cell phone use should be adopted to improve the sleep quality among college students.

[Sleep status associated with psychological and behavioral problems in adolescents and children].

Objective: To examine whether sleep status and social jet lag are related to the mental health behaviors in children and adolescents, providing a reference for preventing and improving children and adolescents' mental health behaviors. Methods: A large cross-section was conducted in Baoan District, Shenzhen, from April to May 2019. A total of 30 188 adolescents and children in grades 1-12 in 14 schools were included. The growth trajectory and health index questionnaire of primary and secondary school students were designed to evaluate the sleep status. Mental health behavior problems among students were accessed using the parents' and students' versions of the Strengths and Difficulties Questionnaire. After controlling for confounding factors of demographic variables, including gender, age, parental education level, academic performance, learning burden, and noise impact, a multivariate logistic regression model was used for statistical analyses. Results: The sleep duration of four grades students were 90.4％,90.1％, 98.2％, and 98.4％, respectively. 19.9％ did not have a post-lunch nap. 19.6％ had a wake-up delay of more than or equal to 2 h weekend morning. 35.1％ had an inconsistent bedtime and 15.5％ had an inconsistent awakening time. The multivariate logistic regression model showed that compared with 8-9 h, the sleep duration of elementary school juniors at night less than or equal to 7 h, 7-8 h increased the risk of psychological behavior problems. The sleep time more than 9 h was negatively correlated with psychological behavior problems. The sleep duration of elementary school seniors less than or equal to 7 h increased the risk of psychological behavior problems. The sleep duration of middle school and high school students less than or equal to 6 h increased psychological behavior problems. The ORs (95％CI) appeared as 2.53(1.85-3.47), 2.41(1.11-5.25), respectively. The ones with a sleep time more than 9 h also increased the risk, and ORs (95％CI) appeared as 2.37(1.40-4.01), 5.38 (1.79-16.1), respectively. Both the absence of post-lunch nap and the nap time less than 0.5 h were risk factors for psychological behavior problems in primary and middle school students. The nap time over 1-2 h was also a risk factor for high school students' psychological behavior problems. Waking up at irregular times in the morning, going to bed at varying times in the evening, and delaying getting up for more than or equal to 2 h on weekends were all risk factors for psychological and behavioral problems among primary and middle school students. The ORs (95％CI) of psychological behavior problems of elementary school juniors and seniors, middle school and high school students were 2.07 (1.45-2.97), 1.57 (1.09-2.26), 2.66 (2.06-3.44), 2.48 (1.96-3.15), respectively. Conclusions: Sleep duration, no post-lunch sleep, and daily intraindividual variability of sleep is positively associated with poor mental health. Additionally, social jet lag is associated with mental health problems in students. It is noted that delaying sleep within half an hour on the weekends of elementary school juniors is significantly associated with an increase in bad mental behavior.

[The development and national norm of the assessment of spinal health of youths].

Objective: To develop the Assessment of Spinal Health of Youths (ASHY), and evaluate its reliability and construct validity and further definite the national norm. Methods: According to literature review and expert consultation, the ASHY included 37 items within 4 dimensions, named symptoms of neck-shoulder and low back, the dysfunction of neck-shoulder and low back, daily risk behaviors and health-seeking behaviors. Between December 2015 and March 2016, a total of 15 096 students were purposively selected from Shenyang, Zhengzhou, Shenzhen and Jiangxi province. Item analysis, factor analysis and reliability evaluation methods were used to select items and evaluate the questionnaire. Between November 2017 and January 2018, a total of 14 500 students were purposively selected from Shenzhen, Zhengzhou, Nanchang and Guiyang. These data were used to develop a national norm of ASHY in adolescents. Results: The ASHY consisted of 4 dimensions covering 34 items. Variance cumulative contribution rate was 68.37%. Internal consistency test showed that Cronbach's α coefficient of the questionnaire was 0.91 and Cronbach's α coefficient of each dimension was between 0.76 and 0.93. The split-half coefficient of the questionnaire was 0.78 and ranged from 0.62 to 0.77 for each dimension. Confirmatory factor analysis results showed that the value of RMSEA was 0.067, and the values of NFI, RFI, CFI, GFI, AGFI were all above 0.80, which had a good fitting degree. The 90th percentile was used as the cutoff point about total scores of 92 for junior high school students, 102 for senior high school students and 98 for the overall middle school students. Conclusions: The ASHY is consistent with the evaluation standard of psychometrics. It can be used as a tool to evaluate the spinal health in adolescents.

[The relationship between migration time and the prevalence of myopia of children and adolescents aged 6-18 years old in Shenzhen].

Objective: To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen. Methods: From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin'an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ2 test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results: The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [OR (95%CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [OR (95%CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [OR (95%CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion: The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.

[Emotional and behavioral problems associated with health-risk behaviors in preschool children].

Objective: To explore the relationship between multiple health-risk behaviors and emotional and behavioral problems in preschool children. Method: From October to November 2017, 27 987 children aged 3 to 6 years from 109 kindergartens of 11 cities from Hubei, Anhui and Jiangsu Provinces in the middle and lower reaches of the Yangtze River were selected by using the cluster sampling method. Finally, 27 200 valid questionnaires were collected. A questionnaire was used to investigate the demographic characteristics, video time and outdoor activities, eating behavior, sleep time, emotional and behavioral problems of parents and children. Multivariate logistic regression model was used to quantify the association between multiple health-risk behaviors and emotional and behavioral problems. Results: Emotional symptoms, conduct problems, hyperactivity, peer problems, total difficulties and prosocial behavior abnormalities were detected in 9.5% (2 587), 9.5% (2 590), 18.2% (4 958), 24.5% (6 670), 11.2% (3 058) and 10.2% (2 770), respectively. Three groups of low, medium and high scores of multiple health-risk behaviors were accounted for 30.6% (8 316), 60.9% (16 568) and 8.5% (2 316), respectively. Multivariate logistic regression model analysis showed that after controlling for the confounding factors, compared with those in the low score group, preschool children in the middle and high score groups had higher risks of emotional symptoms, conduct problems, hyperactivity, peer problems, total difficulties and prosocial behavior (all P values<0.05). Conclusion: Health-risk behaviors are associated with the emotional and behavioral problems of preschool children.

[Effects of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children].

Objective: To explore the effect of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children. Methods: From October to November 2017, 27 987 children aged 3 to 6 years old from 109 kindergartens in 11 cities of Hubei, Anhui and Jiangsu Provinces were selected by using the cluster sampling method. A total of 27 200 valid questionnaires which were completed by subjects' parents were collected. The emotional and behavioral problems of preschool children were collected by "strengths and difficulties questionnaire" and the parental rearing patterns were evaluated by the "Parental Behavior Scale". The differences in emotional and behavioral abnormality rates of preschool children with different characteristics were analyzed; with emotional and behavioral problems as dependent variables and parental support/participation and compulsion/hostility as independent variables, the multivariate logistic regression model was used to analyze the effect of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children. Results: The age of children was (4.35±0.96) years old, and 51.4% of children were 13 975 males. There were 24 634 (90.6%) urban children and 17 916 (65.9%) only children. Both parents with strong support/participation accounted for 14.9%, and those with poor support/participation accounted for 11.9%; both parents with strong compulsion/hostility accounted for 15.2%, and those with low compulsion/hostility accounted for 11.3%. The rates of emotional symptoms, conduct behavior, hyperactive behavior, peer interaction, total difficulty score, and abnormal prosocial behavior of preschool children were 9.5%, 9.5%, 18.2%, 24.5%, 11.2%, and 10.2%, respectively. The multivariate logistic regression model analysis showed that after adjusting for gender, only child, living area, family economic status, mother's age and education level, father's education level, and other factors, compared with fathers/mothers with strong support/participation and low compulsion/hostility and parents with strong support/participation and low compulsion/hostility, preschool children who had fathers/mothers with poor support/participation and strong compulsion/hostility or parents with poor support/participation and strong compulsion/hostility were more likely to have emotional symptoms, conduct behavior, hyperactive behavior, peer interaction, total difficulty score, and abnormal prosocial behavior (P<0.05). Conclusions: Parental rearing patterns and their consistency are related to the emotional and behavioral problems of preschool children.

[Analysis on epidemic situation and spatiotemporal changes of COVID-19 in Anhui].

We used the epidemic data of COVID-19 published on the official website of the municipal health commissions in Anhui province to map the spatiotemporal changes of confirmed cases, fit the epidemic situation by the population growth curve at different stages and analyze the epidemic situation in Anhui Province. It was found that the cumulative incidence of COVID-19 was 156/100 000 by February 18, 2020 and the trend of COVID-19 epidemic declined after February 7 with a change from J-shaped curve to S-shaped curve. As the reporting time of cases might be 3-5 days later than the actual onset time, the number of new cases in Anhui province actually began to decline around February 2 to February 4, 2020.

[Analysis on risk factors of screen time among Chinese primary and middle school students in 12 provinces].

OBJECTIVE: To investigate the characteristics of screen time and its risk factors in Chinese primary and middle school students. METHODS: During April 2012 and June 2012, according to the geographical distribution, the stratified random cluster sampling method was used to select 4 provinces from eastern, central and western China, respectively. The convenience sampling method was used to select 2 primary and middle schools from urban, 2 primary and middle schools from rural in each province. In each school, all grades were included, and 2 classes were selected in each grade. A total of 51 866 students or parents were selected as study participants, and 43 771 questionnaires were valid. Information on demographics, academic performance, screen time (TV, computer and cellphone) at weekdays and weekends and the prevalence of the high screen time were compared, multivariate logistic regression was used to analyze the association between screen time >2 h/d and potential influential factors. RESULTS: The percentage of students with screen time >2 h/d at weekdays and weekends were 16.2% (7 082/43 771) and 41.5% (18 141/43 771) (χ(2)=6 280.14, P<0.001), respectively. The distribution of P50 (P25-P75) for screen time at weekdays and weekends were 0.9(0.4-1.6) and 1.8(1.0-3.0) (Z=-131.26, P<0.001), respectively. The results of multinomial logistic regression analysis showed that, at weekdays, subjects characterized as primary school students, boys, urban area, living in western area and sufficient vigorous physical activity ≤2 d/w had higher risk for screen time >2 h/d than those characterized as elementary school students, girls, rural area, living in eastern area and sufficient vigorous physical activity >3 d/w, odds ratio were 2.01, 1.54, 1.21, 1.09, and 1.07, respectively (P<0.05 for all); subjects characterized as a normal or worse self rating academic performance had higher risk for screen time >2 h/d than those characterized as a good self rating academic performance, odds ratioes were 1.24 and 1.73, respectively (P<0.05 for all); subjects characterized as paternal education level as elementary school, middle school, high school or secondary school had higher risk for screen time >2 h/d than those characterized as paternal education level as college school or high, odds ratioes were 1.41, 1.47 and 1.52, respectively (P<0.05 for all); subjects characterized as maternal education level as elementary school, middle school and high school or secondary school had higher risk for screen time >2 h/d than those characterized as maternal education level as college, odds ratioes were 1.40, 1.52 and 1.47, respectively (P<0.05 for all). At weekends, subjects characterized as primary school students, boys, urban area and sufficient vigorous physical activity ≤2 d/w had higher risk for screen time >2 h/d than those characterized as elementary school students, girls, rural area and sufficient vigorous physical activity >3 d/w, odds ratioes were 2.11, 1.51, 1.20 and 1.05, respectively (P<0.05 for all). At weekends, subjects characterized as a normal or worse self rating academic performance had higher risk for screen time >2 h/d than those characterized as a good self rating academic performance, odds ratioes were 1.09 and 1.26, respectively (P<0.05 for all); subjects characterized as paternal education level as elementary school, middle school, high school or secondary school had higher risk for screen time >2 h/d than those characterized as paternal education level as college school or high, odds ratioes were 1.29, 1.30 and 1.19, respectively (P<0.05 for all); subjects characterized as maternal education level as elementary school, middle school had higher risk for screen time >2 h/d than those characterized as maternal education level as college school or high, odds ratioes were 1.19 and 1.16 and, respectively (P<0.05 for all). CONCLUSION: The prevalence of screen time >2 h/d is high; screen time at weekdays is longer than weekends, and there are significant differences among different sexes, urban or rural areas, living areas, self rating academic performance, parents education levels and physical activity groups.