Objective: To explore the relationship between pubertal knowledge-attitude-practice(KAP) and quality of life (QoL) of left-behind children in adolescence, and to provide a scientific reference for making measures to improve QoL of left-behind children. Methods: In December 2017, 3 524 left-behind children from 5 primary schools and 5 middle schools in Chongqing were selected by stratified cluster sampling method carry out the Quality of Life Scale of adolescent children and the Questionnaire of Adolescent Knowledge and Belief. Results: The scores of total QoL, physicaland social dimensions of left-behind children[(140.81±17.19)(30.05±5.07)(50.99±8.32)points, respectively]were lower than those of non-left-behind children[(141.81±17.53)(30.35±5.06)(51.73±8.44)point, respectively](P<0.05). Gender, School period, puberty timing, family rearing pattern and economic status had significant influence on the QoL of left-behind children (P<0.05). The adolescent attitude and behavior had a positive effect on total QoL and the scores of physical, psychological, social and adolescent dimensions of left-behind children(B=0.62, 0.08, 0.11, 0.30, 0.13；0.77, 0.11, 0.20, 0.26, 0.19, P<0.01); and knowledge had a positive effect on the adolescence of QoL(B=0.04, P<0.01). Conclusion The adolescent attitude, behavior and quality of life of left-behind children were positively correlated. Strengthening adolescent health education for left-behind children, focusing on conveying correct adolescent attitude to students, and promoting the transformation of correct attitude to positive practice, can improve the QoL of adolescent left-behind children.

Objective: To understand the health literacy level and its influencing factors among middle school students in Chongqing, and to provide a basis for health promotion. Methods: Using stratified cluster random sampling and a self-designed questionnaire, we conducted a survey among 8 449 junior and senior high school students from four districts and counties in Chongqing municipality from November to December 2019. Results: The attainment rates of total health literacy, functional health literacy, interactive health literacy, and critical health literacy among middle school students in Chongqing were 67.96%, 75.12%, 50.24%, and 72.21%, respectively. Among the 12 factors, low rates were observed in health decision-making, reasonable nutrition, and communication (41.52%, 46.09% and 62.18%, respectively). After controlling for related confounding factors, the results of the multivariate Logistic regression analysis indicated that the following factors affected the total health literacy of middle school students: the investigated region (OR=1.20); school segment (OR=1.35); relationship with mother (OR=1.52); relationship with teacher (OR=2.20); number of close friends (OR=1.68); and health education course (OR=1.52) (P<0.05). Conclusion The health literacy level of middle school students in Chongqing is relatively low. Therefore, it is necessary to focus on improving interactive health literacy in order to promote the healthy development of middle school students.

Objective: To determine the relationship between peer attachment and quality of life among adolescents in Chongqing, to provide scientific basis for intervention of quality of life. Methods: A total of 6 073 respondents were selected from 5 middle schools and 6 primary schools in a district of Chongqing in December 2017 by stratified cluster sampling method. The revised Chinese version of Adolescent Attachment Questionnaire (IPPA-R) Peer Attachment Subscale and Adolescent Children s Quality of Life Scale were used to conduct the survey. Results: The total score of life quality of students with secure attachment type (144.97±17.39) was significantly higher than that of students with insecure attachment type(136.45±17.75)(t=18.90，P<0.01). The scores of four dimensions of life quality of students with secure attachment[(30.40±5.11)(39.42±6.42)(53.45±7.99)(21.73±3.69)] were significantly higher than those of students with insecure attachment[(29.54±5.15)(37.87±6.66)(49.02±8.69)(20.02±3.60)](P<0.05). Multivariate stepwise regression analysis showed that peer attachment was correlated with physical, psychological, social, adolescent dimensions and the total score of life quality(B=0.28，0.03，0.05，0.14，0.05，P<0.05). Conclusion Adolescent peer attachment is positively correlated with the total score and specific dimensions of life quality. Improving the safety of peer attachment is helpful to improve life quality among adolescents.

Objective: To analyze the effect of the peer education intervention model on improving adolescent knowledge, attitudes, and behavior among primary and secondary school students, so as to provide a basis for exploring adolescent based health education methods. Methods: A group of students from grades 4-5 and 7-8 were selected from two primary schools and two middle schools in a district of Chongqing. The sample was divided into an intervention group (n=685) and a control group (n=821), and the intervention group received peer education for one year. Basic information related to the pre and post intervention, and data regarding knowledge, attitudes, and behavior were investigated using a basic situation questionnaire and an adolescent knowledge attitudes behavior questionnaire that were designed by the research group. Results: The results obtained after the intervention showed that the scores of adolescent knowledge attitudes behavior and the total scores of the intervention group increased from (10.00±6.39) (39.19±5.79) (28.69±4.24) and (77.89±12.66) to (15.65±5.87) (42.06±5.95) (29.95±4.05) and (87.66±12.93), and the difference was statistically significant (P<0.01). After the intervention, increasing of adolescent knowledge attitudes behavior and the total scores of the intervention group were (5.64±5.61) (2.87±6.72) (1.26±4.55) (9.77±11.91), respectively, which were higher than those of the control group [(4.42±5.15) (2.08±5.84) (0.86±4.24) (7.36±10.70)]. Except for adolescent behavior, increasing of other scores were statistically significant (t=-4.39,-2.40,-1.73,-4.09,P<0.05). Conclusion Peer education shows certain effects on improving adolescent knowledge and positive attitudes, although similar effect on adolescent behavior needs further study.