title: [Myopia prevalence and influencing factor analysis of primary and middle school students in our country].
abstract: OBJECTIVE
  To explore the situation and the affect factors of myopia and scientificalness and effectiveness of eye exercises about primary and middle school students.
  
  
  METHODS
  Through the random cluster sampling method, 20 000 students of 90 schools including key and non-key primary or junior or senior school in country and city of shandong, qinghai, yunnan, Shanghai and wenzhou were random selected. Primary students is 11 246 junior students is 3673 senior students is 4220.We surveyed related situation of eye exercises, myopia. a total of 19 139 valid questionnaires were received. By random sampling stratification method, freshmen were selected and retrospective surveyed. 929 freshmen have normal vision when they graduated primary school. 338 freshmen have normal vision when they graduated primary school.2 groups are considered analysis object, and Myopic students of the former in junior school stages and the latter in senior school stages are considered case group, normal vision are considered control group, and then through the Logistic multiple stepwise regression analysis, a regression analysis model is established.
  
  
  RESULTS
  This survey show that myopia prevalence was 13.7% of primary students, 42.9% of junior students, 69.7% of senior students. According to the significant P < 0.001, Rsquare = 0.14, the result shows that the model has the significant statistical significance. Among the influence factors, whether to long-term excessive use eye is the most significant, and following by outdoor activities and gender. A chi-square test χ(2) = 0.371 and P = 0.543 show that doing eye exercises was not statistically significant to prevalence of myopia.
  
  
  CONCLUSIONS
  The influence factors are changed, and the preventive methods should be adjusted with the social environment.
authors.affiliation: Institute for research about public policy and social deuelopment, Wenzhou Medical College, Wenzhou 325035, China. wz.xie@163.com
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Xie
authors.forename: Zuo-Kai
authors.initials: ZK
authors.lastname: Xie
authors.forename: Fen
authors.initials: F
authors.lastname: Zhou
authors.forename: Liang
authors.initials: L
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009216:Myopia / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D018434:Sickness Impact Profile; D013334:Students; D011795:Surveys and Questionnaires