title: [Prevalence of myopia and influencing factors among primary and middle school students in 6 provinces of China].
abstract: OBJECTIVE
  To understand the prevalence of myopia in primary and middle school students in 6 provinces and the possible influencing factors.
  
  
  METHODS
  Primary and middle school students were selected through multistage cluster sampling in 60 primary and middle schools in 6 provinces in China. The questionnaire survey and eyesight test were conducted among all the students selected according to the national student's physique and health survey protocol. Pearson chi-square test and binary multivariate logistic regression analysis were done to identify the influencing factors for myopia in students.
  
  
  RESULTS
  The prevalence of myopia among primary and middle school students surveyed was 55.7%, the gender specific difference was statistically significant (59.7% for girls, 51.9% for boys) (P<0.01). The prevalence of myopia increased with age obviously. The prevalence was 35.8% in age group 6-8 years, 58.9% in age group 10-12 years, 73.4% in age group 13-15 years and 81.2% in age group 16-18 years, the differences were statistically significant (P<0.001). Single factor and multivariate analysis showed that parents' myopia, distance between computer screen and eyes, distance less than 30 cm between eyes and book while reading, distance less than 10 cm between chest and the table edge while studying, distance less than 3 cm between fingers and pen tip, sleep time, average outdoor activity time during last week, school sport activities in the afternoon, the size of television set at home, time spent on watching TV and playing computer were the influencing factors for myopia.
  
  
  CONCLUSIONS
  The prevalence of myopia is till high in primary and middle school students. Myopia is associated with both genetic factors and individual eye health related behaviors.
authors.affiliation: Institute of Child and Adolescent Health, Peking University, Beijing 100191, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Institute of Child and Adolescent Health, Peking University, Beijing 100191, China.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Institute of Child and Adolescent Health, Peking University, Beijing 100191, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Institute of Child and Adolescent Health, Peking University, Beijing 100191, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zou
authors.affiliation: Institute of Child and Adolescent Health, Peking University, Beijing 100191, China.
authors.forename: Xiangkun
authors.initials: X
authors.lastname: Meng
authors.affiliation: Department of Maternal and Child Health, School of Public Health, Anhui Medical University, Anhui Provincial Laboratory of Population Health and Eugenics, Hefei 230032, China.
authors.forename: Fangbiao
authors.initials: F
authors.lastname: Tao
authors.affiliation: Department of School Health, Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Luo
authors.affiliation: Department of Maternal and Child Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Jing
authors.affiliation: Liaoning Provincial Health Supervision Authority, Shenyang 110005, China.
authors.forename: Dehong
authors.initials: D
authors.lastname: Pan
authors.affiliation: School of Public Health, Central South University Changsha 410008, China.
authors.forename: Jiayou
authors.initials: J
authors.lastname: Luo
authors.affiliation: Public Health School of Tianjin Medical University, Tianjin 300070, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Maternal & Child Care and Adolescents Health, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Maternal & Child Care and AdolescentsHealth, School of Public Health, Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D015438:Health Behavior; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009216:Myopia / Q000453:epidemiology*; D010290:Parents; D015995:Prevalence; D012574:Schools; D012890:Sleep; D013334:Students; D011795:Surveys and Questionnaires