Objective: To understand the moderating effect of cohabitation with parents on the association between peer dating behavior and sexual behaviors among secondary vocational school students, so as to provide a scientific basis for preventing sexual behaviors among secondary vocational school students. Methods: From March to April 2021, an electronic questionnaire survey was conducted among 3 180 students from 6 vocational schools in Shanghai (urban, suburban, exurban) and Shaanxi (Shangluo, Ankang, Baoji) using cluster sampling. Spearman correlation analysis was used to investigate the relationship of cohabitation with parents, peer dating behavior and sexual behaviors among secondary vocational school students. Binary Logistic regression analysis was performed to investigate the role of cohabitation with parents on peer dating behavior and sexual behaviors among secondary vocational students. Results: There was a significant negative between cohabitation with parents and sexual ( r =-0.04); and there was a positive correlation between peer dating behavior and sexual behaviors ( r =0.24), as well as cohabitation with parents and peer dating behavior ( r =0.04)( P <0.05). Multivariable Logistic regression analysis showed an association between peer dating behavior and the occurrence of sexual behaviors ( OR=2.79-12.95, P <0.05). Cohabitation with parents played a moderating role in the association between peer dating behavior and sexual behaviors, and a signification interaction was found between cohabitation with parents and reporting that a small part or about half of their peers had dating behavior ( OR =0.48, P <0.05). Conclusions The more peers dating behavior are associated with a higher risk of sexual behaviors among secondary vocational school students, and cohabitation with parents can partly reduce this risk. School and family sexuality education for secondary vocational students should be strengthened to improve their interpersonal skills and decision-making, and ability to resist peer pressure, so as to reduce their risk of sexual behaviors.

Objective: To examine the association between parent-child relationships and bullying behaviors among junior high school students, and to explore the moderating effect of community cohesion, so as to provide evidences for bullying intervention strategies. Methods: From November to December 2017, a cluster sampling method was used to survey 1 589 students in grades 6- 8 from three junior high schools in Jing an District,Shanghai. Anonymous electronic questionnaires collected data on parent-child relationships, community cohesion, and bullying behaviors. Multivariate Logistic regression analyzed the associations and moderation effects. Results: The prevalence of bullying behaviors among junior high school students was 7.80%. Spearman correlation analysis revealed negative associations between both parent-child relationships ( r =-0.13) and community cohesion ( r =-0.10) with bullying behaviors, while parent-child relationships positively correlated with community cohesion ( r =0.29) (all P <0.01). Junior high school students with positive parent-child relationships and higher perceived community cohesion showed lower risks of bullying behaviors ( OR=0.51, 95%CI =0.36-0.72; OR=0.58, 95%CI =0.45-0.76), with a significant interaction effect between the two factors (all P <0.05). Conclusions Positive parent-child relationships and community cohesion are negatively associated with bullying behaviors in middle school students. Supportive family relationships help reduce bullying, while stronger community cohesion enhances the protective effect of positive parent-child relationships against bullying.

Objective: To understand sexual and reproductive health knowledge, access to sexuality education and associated factors among secondary vocational school students in Shanghai Municipality and Shaanxi Province, so as to provide a scientific basis for conducting sexuality educaiton in vocational schools. Methods: A crosssectional survey was conducted among 3 180 students in grades 1-3 selected by cluster sampling during April to June 2021 in six secondary vocational schools from three cities of Shanghai and Shaanxi (Shangluo, Ankang, Baoji). Participants were investigated through online questionnaire survey, inlcuding demographic characteristics, household information, sexual health at home and school, knowledge on sexual and reproductive health. Both t test and Chisquare test were used for group comparisons, and multivariate ordial Logistic regression was used to explore possible risk factors for sexual and reproductive health score in quartiles. Results: Respondents average score was (51.36±21.61), with the highest score on sexual harassment/sexual abuse (66.45±42.27) and the lowest score on reproduction and physiology (47.67±31.94) and contraception (43.85±26.81). Although significant differences were observed between two study sites, the primary source of knowledge in both sites was schools/teachers, followed by the Internet or friends; the main theme of school sexuality education was puberty development and health care (more than 80%); the most frequently reported topic between respondents and their parents in both sites was interpersonal relationships (more than 55%), and there were significant differences in the reporting rates of secondary vocational school students between the two regions(χ2=28.56，32.02，P<0.05). The results of multivariable Logistic regression analysis showed that residential area, gender, grade, registered residence, number of sexual related topics communicated with parents, number of subjects received from school sexuality education, and reported information sources from classmates/friends, books/magazines/newspapers, internet and communities were related to knowledge level of respondents (OR=1.62, 0.72, 1.20, 1.58, 2.09, 1.17, 1.18, 1.66, 1.62, 1.69, 1.22, P<0.05). Conclusions Vocational students of Shanghai and Shaanxi have poor sexual and reproductive health knowledge and limited access to school and family sexuality education. It is necessary to strengthen sexuality education for secondary vocational school students.

Objective: To explore the relationship between body image and adverse childhood experiences (ACEs) in adolescents. Methods: A total of 1 701 adolescents in grade 6-8 in three middle schools in Shanghai were selected by stratified cluster sampling, and were investigated anonymously using computer assisted self interview approach. Information including demographic characteristics, body image satisfaction, and ACEs were collected. The Chi square test and multivariate Logistic regression were used to explore the relationship between adolescent body image satisfaction and types of ACEs. Results: About 60.73% of the respondents were satisfied with their body image, with higher satisfaction among boys(66.16%) than among girls(55.13%)( χ 2= 21.70 ， P <0.01). About 79.19% of the respondents had experienced at least one ACE, and respectively 61.61%, 65.14% and 21.58 % of them had experienced abuse, neglect and family dysfunction. Multivariate Logistic regression analysis indicated that experiencing at least one ACE, abuse, neglect and family dysfunction were all related with low body image satisfaction among girls( OR =0.33- 0.57 , P <0.01), while among boys neglect,having 3 or more than 4 ACEs were found to be associated with body image satisfaction ( OR =0.54-0.64, P <0.05). The cumulative effects of ACEs on adolescent body image were observed. Conclusion Different types of ACEs are associated with body image in adolescents, ACEs have cumulative effects on adolescent body image, which shows gender differences.Screen of ACEs and improvement of family nurturing environment should be highlighted among adolescents, especially among girls.

Objective: To explore the relationship between gender role attitudes (GRA) and adolescent depression to provide evidence for the promotion of mental health among adolescents. Methods: A total of 1 549 students from grades 6 to 8 in three public middle schools in Jing an District of Shanghai were selected by stratified cluster sampling. The baseline and follow up surveys were conducted by anonymous electronic questionnaire on mobile tablets from November to December in 2017 and 2018, respectively. The GRA Scale and the Depression Scale were used to collect subjects attitudes towards traditional role assignment and power inequality between men and woman and depression in family and sexual relationships. The multivariate Generalized Estimating Equations (GEE) model was adopted to examine the relationship between GRA and depression. Results: The mean score of the GRA Scale was (2.52±0.83) and (2.29±0.86), while the score of Depression Scale was (15.92±5.08) and (16.48±5.29), in the baseline and follow up survey, respectively ( P <0.05). After controlling the covariates of age, bullied experience, body image, social cohesion, etc., the multivariate GEE model indicated traditional GRA was significantly associated with a higher risk of depression among both boys and girls ( β boys =0.38, β girls =0.41, P <0.05). Conclusion Traditional GRA may increase the risk of depression in adolescents, suggesting that cultivating a positive and equal GRA among this population group may help to prevent depression.

Objective: To explore the prevalence of sexting among secondary vocational school students and to examine the correlation between sexting and mental health, so as to provide evidence for prevention and intervention on adolescents mental health. Methods: In April 2021, three secondary vocational schools from central urban area, outskirts and outer suburbs in Shanghai, among 1 580 students were selected by cluster sampling. Results: The proportions of students who received and who forwarded others private photos or videos were 11.96% and 2.78%, respectively. The proportion of students who sent others personal photos or videos was 2.54%. And the proportions of boys were higher than those of girls ( χ 2=45.89, 24.09, 6.66, P <0.01). The results of multivariable Logistic analysis showed that compared with those who had never sexted, students who had ever had any sexting were at higher risk of anxiety ( OR=2.40, 95%CI =1.59-3.61), depression( OR=1.86, 95%CI =1.25-2.75), non suicidal self injury intention ( OR=2.34, 95%CI =1.48-3.69) and suicidal intention ( OR=2.96, 95%CI =1.83-4.79)( P < 0.05 ). Conclusion There is a significant correlation between sexting and mental health among secondary vocational school students. The latent risks of sexting should be included in the curriculum of comprehensive sex education for teenagers to enhance their media literacy and decision making capability, so as to prevent sexual assault or abuse caused by sexting and promote sexual and reproductive health and as well as mental health of adolescents.

Objective: To explore the association between mothers reactions to adolescents exposure to intimate shots and pornography use of junior high school students, and to provide references for family communications on sexual topics in similar scenarios. Methods: A total of 1 760 students from grade 6 to 8 in three junior high schools in a certain district of Shanghai were selected by cluster sampling. Self-filled questionnaires on tablets were used to collect data. Results: The proportion of junior high school students who watched pornography was 26.36%(464), and that of boys (29.83%，270/905) was higher than of girls (22.69%，194/855). Most junior high school students believed that mothers reactions to adolescents exposure to intimate shots would be “taking the opportunity to educate teenagers not to do this” (30.54%) or “avoiding adolescents watching intimate shots” (42.24%). The results of multivariable analysis showed that comparing with junior high school students who believed that mothers would “watch together without making any comments ”, students who believed that mothers would “take the opportunity to educate teenagers not to do this”(OR=0.43, 95%CI=0.29-0.64) and “avoid adolescents watching intimate shots”(OR=0.56, 95%CI=0.39-0.80) were at lower risk of viewing pornography (P<0.01). Conclusion There is a significant correlation between junior high school students pornography use and mothers possible reactions to adolescents exposure to intimate shots. Family sex education and parental monitoring should be emphasized, and parents awareness of communicating sexual issues with adolescents should be strengthened.

Objective: To explore the association between adverse childhood experiences (ACEs) and adolescent alcohol use and to provide evidence for prevention and intervention. Methods: A total of 1 550 students from grades 6 to 8 in three public middle schools in a district of Shanghai were selected by stratified cluster sampling method. The baseline and follow up investigation were conducted by anonymous electronic questionnaire in mobile tablet from November to December in 2017 and 2018, respectively. The latent class analysis (LCA) was applied for the classification of ACEs, while the multivariate generalized estimating Equations (GEE) model was adopted to examine the association between ACEs and adolescent alcohol use. Results: The ACEs was divided into 3 classes by LCA: high exposure (8.97%), abuse and neglect (38.97%), low exposure (52.06%). The multivariate GEE model indicates the risk of alcohol drinking among adolescents in high exposure and abuse and neglect classes were significantly higher than their counterparts in low exposure class ( OR=2.65, 95%CI=1.72-4.07; OR=1.50, 95%CI =1.14-1.96, respectively). Conclusion The effect of ACEs on alcohol use may vary across different latent classes. Supportive childhood environment may contribute to decrease the risk of adolescent drinking behavior.

Objective: To explore the influence of impulsive traits of adolescent on pornography use through the analysis of the Global Early Adolescent Study(GEAS) longitudinal survey data collected in Shanghai, and to provide evidence for adolescent sexual health promotion. Methods: Totally 1 512 students from grades 6 to 8 in three middle schools in a district of Shanghai were selected for the present study by stratified cluster sampling method. Baseline and two-wave follow-up investigation were conducted between 2017 and 2020. Three waves of pornography use and social demographic information were collected using electronic questionnaire through tablets while impulsivity were tested only once during the follow-up in 2018 using the paper and pencil based Barratt Impulsivity Scale, version11 (BIS-11). General statistical description and panel data statistical description, as well as multilevel mixed effect linear model were used to do the analysis. Results: About 32.7% (494) of the adolescents reported the experience of watching pornography in threewave analysis. Boys were more impulsive than girls in the motor subscale (16.33±3.25, 15.66±2.93, t=4.13, P<0.01) while girls were more impulsive than boys in the nonplanning subscale (23.65±5.11, 22.83±5.21, t=-3.03, P<0.01). Mixed effect linear model result showed that impulsivity was correlated with pornography use(β=0.001, P<0.01); higher impulsivity in motor and attention were correlated with more frequent pornography use(P<0.01). Being female, perceived more parental awareness and perceived care from school adults would decrease the use of pornography while spent more than 3 hours on internet would increase the use of pornography (P<0.01). Conclusion There are stable correlations between impulsivity and pornography use. It is urgent to equip young adolescents with the necessary ability to distinguish the good from the bad in the mass and internet media world.

Objective: To explore the gender stereotype in early adolescence and the potential influencing factors. Methods: Stratified cluster sampling method was adopted to recruit students of grade 6-8 in three middle schools of Shanghai during November to December, 2017. Students were surveyed anonymously using Computer Assisted Self-Interview approach regarding geder stereotype and associated factors. Results: Average gender stereotype score was (3.32±0.75), with boys(3.43±0.75)higher than the girls(3.20±0.72)(t=6.37, P<0.05). The "agreement" proportion was highest among gender stereotypes items which reflect personality characteristics such as "it’s important for boy to be strong and determined" "girls should be like a lady" and "girls were expected to be submissive"(60.99%，50.79%，43.95%), and the "agreement" proportion among boys increased with age, while decreased in girls. Boys who had sisters or recent bullying behaviors showed more gender stereotype[β(95%CI)=0.19(0.05-0.33), 0.39(0.12-0.67)]. Girls whose parents allowed to go to opposite sex homes alone had less gender stereotype, however, the gender stereotype became stronger when girls had more female peers[β(95%CI)=-0.22(-0.41--0.03),0.04(0.00-0.07)]. Conclusion The young adolescents, especially boys, show certain level of gender stereotype. The normal heterosexual friendships and safe campus environments would help promote young adolescents to establish equal gender beliefs.