Objective: To analyze the association between eye use behavior and self reported myopia in middle and high school students, and provide the scientific basis for the prevention and control of myopia. Methods: A total of 14 872 middle and high school students was selected from four provinces and cities from December 2015 to March 2016, including Jiangxi(Nanchang,Yintan,Dexing), Liaoning(Shenyang), Guangdong(Shenzhen), Henan(Zhengzhou) provinces. A self administrated questionnaire was used to collect the basic information, self reported myopia and eye use behaviors among middle and high school students. The Chi square tests were applied to compare the differences in self reported myopia among middle and high school students with different characteristics. Multivariate binary Logistic regression models were used to analyze the association between eye use behavior and self reported myopia in middle and high school students. Results: The self reported myopia rate of middle and high school students was 68.5%, with 59.7% and 78.6% for junior high school students and senior high school students, respectively. After adjusting for the potential confounders, the Logistic regression models showed that middle and high school students who read and write with their heads down ( OR =1.94, 2.32),middle and high school students who lie down or lie on stomach when using their eyes ( OR =1.27, 1.28) had a higher risk of self reported myopia ( P <0.01). There was a negative correlation between eye use distance (reading and writing distance, distance from eyes to TV, mobile phone, or tablet) and self reported myopia ( OR =0.73, 0.70, 0.81; 0.61, 0.66 , 0.76) in middle and high school students ( P <0.01). In addition, the risk of self reported myopia was lower in middle school students with longer eye to computer distance ( OR=0.77, P <0.01). Conclusion There is a significant association between eye use postures, eye use distance and self reported myopia in middle and high school students. Health education for the risk and behavior factors of myopia should be actively promoted to ensure the visual health of children and adolescents.

Objective: To develop the Assessment of Smartphone Multitasking for Adolescents (ASMA) and evaluate its reliability and construct validity, so that to provide an evaluation tool for relevant epidemiological studies. Methods: Based on literature review, expert based judgement, and group discussion, the self administered ASMA identified 3 dimensions named smartphone activities and non-media activities multitasking, smartphone activities and other media activities multitasking, and smartphone functional use multitasking, which initially included 27 items. From October to December 2021, 5 566 college students were selected from 7 regions, including Liaoning, Shanxi, Henan, Shanghai, Chongqing, Shenzhen, and Yunnan by multi stage cluster sampling method, and item analysis, factor analysis, and reliability evaluation were used to screen items and evaluate reliability and validity. Results: The final version of AMSA contained 3 dimensions covering 26 items. The variance cumulative contribution rate was 59.63 %. The internal consistency test showed that Cronbach s alpha coefficient for the questionnaire was 0.944, and ranged from 0.838 to 0.928 for each dimension. The split half coefficient of the questionnaire was 0.849 and ranging from 0.781 to 0.874 for each dimension. The results of confirmatory factor analysis showed that the root mean square error of approximation (RMSEA), comparative fit index (CFI), and Tucker Lewis index (TLI) of the questionnaire were 0.068, 0.901, and 0.891, respectively, which had which had a good fitting degree. The results of Pearson correlation analysis showed that the criterion validity of the questionnaire was good ( r=0.206-0.351, P <0.01). Conclusion The ASMA is consistent with the evaluation standard of psychometrics and can be used as an assessment tool to evaluate smartphone multitasking behaviors in adolescents.

Objective: To assess screening method for myopia among Chinese school age children and adolescents, and to provide scientific evidence for an appropriate protocol for vision screening. Methods: According to technical protocols of 2014 Chinese National Survey on Students Constitution and Health, a total of 1 725 primary and middle school girls aged 9 to 13 years old from Suzhou, Hefei and Chizhou of Anhui Province were selected. Basic information and menarche were collected by questionnaires. Distance visual acuity and subjective refraction were used for screening myopia. And multivariate Logistic regression analysis was used to analyze the relationship between menarche and screening myopia. Results: The detection rate of screening positive myopia of girls aged 9-13 years in Anhui province was 62.5%(1 078). The ratio of screening myopia was significantly higher in urban girls (71.0%) compared with suburban girls(54.6%), and higher in girls with homework time >2 h compared (70.8%) with homework time 1-2 h and <1 h (68.4%, 54.9%) groups ( χ 2=49.50, 37.88, P <0.01). The detection rate of screening myopia between different menarche groups was only statistically significant among girls aged 9 and 13 years ( χ 2=4.75, 11.22, P <0.05). Multivariate Logistic regression analysis showed that menarche was significantly associated with screening myopia ( OR =2.06, 95% CI =1.68- 2.52 ). After controlling age and BMI, the association remained ( P <0.05). After further controlling family residence background and homework time, the association diminished ( P >0.05). Conclusion Menarche is closely associated with screening myopia among girls in selected age groups, future cohort studies are needed to focus on prevention and control of myopia during pubertal development.

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.

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.

Objective: To simplify the psychological domain of Multidimensional Sub-health Questionnaire of Adolescents (MSQA),which includes 39 items and develop the Brief Instrument On Psychological Health of Youths(BIOPHY), as well as to evaluate the predictive validity of the BIOPHY. Methods: A total of 14 221 students were recruited from Shenyang,Xinxiang,Guangzhou,and Chongqing by using multistage stratified cluster random sampling to participate in the study. A combination of item analysis,factor analysis and reliability evaluation were used to screen items and evaluate the questionnaire. Meantime, data from 14 500 adolescents from Shenzhen,Nanchang,Zhengzhou and Guiyang in 2017 were used to develop a cut-off point and to evaluate its predictive validity. Results: On the basis of item analysis,BIOPHY consisted of 15 items. Variance cumulative contribution rate was 57.39%; internal consistency test showed that the total questionnaire Cronbach α coefficient was 0.928. The split-half coefficient of the total questionnaire was 0.909. The 90th percentile of total scores was used as the cutoff point of BIOPHY. The results of multivariate logistic regression analysis showed that students with psychological health symptoms were at significantly higher risk of depressive symptoms (OR=10.53,95%CI=9.28-11.94),suicide ideations (OR=5.77,95%CI=5.15-6.46),suicide plans (OR=6.09,95%CI=5.39-6.89) and suicide attempts (OR=4.80,95%CI=4.04-5.69) than normal counterparts. Conclusion The BIOPHY is consistent with the evaluation standard of psychometrics. The predictive validity of BIOPHY is good and could be used in the future researches focusing on adolescent mental health.