Evaluation of extending outdoor time on myopia prevention among school children

Objective To explore the impacts on myopia prevention among school children of extending outdoor activities time and to provide suggestions to improve the intervention protocol. Methods All the school children from 2 urban schools and 3suburban schools from 16 districts in Beijing were selected as the subjects using stratified cluster sampling method. The students of each school were randomly allocated to trial group and control group. The students in the trail group( 295) were extending their outdoor activities' time,while the students in the control group( 311) didn't experience that way. The diopter of computer optometry to non mydriatic condition was used as the diagnosis criteria of myopia. The software of SPSS 17.0 was used for the statistics. Logistic regression model and Analysis of Covariance was used to evaluate the effect of the intervention. Results Logistic regression analysis showed that compared with the control group,the OR of primary school students in the intervention group suffered from myopia was 0.586( 95%CI = 0.402-0.853). According to the gender stratification,extending outdoor activities' time for male students was good for the protection of the vision( OR = 0.513,95%CI = 0.297-0.885). And the Covariance analysis results were consistent with the results of Logistic regression analysis. Conclusion Extending outdoor activities' time,especially for boys,can control the progress of myopia to some degree.