title: Prevalence of asthenopia and its risk factors in Chinese college students.
abstract: OBJECTIVE
  To determine the prevalence of asthenopia and identify any associated risk factors in the college students in Xi'an, China.
  
  
  METHODS
  From April to September 2012, 1 500 students from five universities in Xi'an were selected according to a multi-stage stratified cluster sampling method. Data on demographic features, lifestyle or dietary habits, health status, living environment conditions, sleep and mental status, and asthenopia symptoms were collected through a self-administered validated questionnaire. Univariate logistic regression and multivariate logistic regression analysis modified by the factor analysis were performed to evaluate risk factors for asthenopia.
  
  
  RESULTS
  Fifty-seven percent of the college students complained of asthenopia. Statistically significant risk factors for asthenopia in the univariate analysis included 13 variables. Multivariate analysis revealed a significant relationship between the use of computer and asthenopia (OR 1.21, 95%CI: 1.09 to 1.35). Good sleep and mental status (OR 0.86, 95%CI: 0.76 to 0.97), good living environment conditions (OR 0.67, 95%CI: 0.60 to 0.76), and high intake of green leafy vegetables (OR 0.89, 95%CI: 0.80 to 0.98) were found to be strong predictors of decreasing the occurrence of asthenopia complaints.
  
  
  CONCLUSIONS
  Asthenopia symptom appears to be common among college students; and it is strongly associated with computer use, psychosocial state, environment conditions and dietary habits, suggesting that additional studies are warranted to verify these risk factors and establish prevention guidelines, especially for college students.
authors.affiliation: School of Public Health, Xi'an Jiaotong University College of Medicine, 76 Yanta West Road, Xi'an 710061, Shaanxi Province, China.
authors.forename: Cheng-Cheng
authors.initials: CC
authors.lastname: Han
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.forename: Ru-Ru
authors.initials: RR
authors.lastname: Liu
authors.forename: Zhong-Hai
authors.initials: ZH
authors.lastname: Zhu
authors.forename: Rong-Bin
authors.initials: RB
authors.lastname: Yu
authors.forename: Le
authors.initials: L
authors.lastname: Ma
keywords: asthenopia; college student; epidemiological feature; risk factor