[A longitudinal study on the progression and influencing factors of myopia in primary school students from grade one to grade three in Hubei Province].

To investigate the longitudinal epidemiological characteristics of myopia in primary school students from grade one to grade three in Hubei province, and to analyze the main factors affecting the occurrence and development of myopia, so as to provide the direction and theoretical basis for the prevention and control of myopia in children and adolescents. Longitudinal study. A total of 13, 244 primary school students from grade one to grade three in 17 prefectures and forest districts of Hubei province were included in the study by means of random stratified cluster sampling. Among them, there were 7, 331 boys and 5, 913 girls with an age of (7.7±1.0) years. The same group of students were followed up for two years from October 2017 to October 2019 to complete three data collections. All included subjects underwent visual acuity examination, which required further automatic computer optometry after using cyclopentolate hydrochloride eye drops if the visual acuity was less than 1.0. In the questionnaire, the general situation and eye behavior of the included subjects were collected. The Chi-square test was used to compare the prevalence of myopia among different genders,different reproductive history and grades. The Kruskal-Wallis H test was used to compare the difference in the mean spherical equivalent refraction, and logistic regression was used to analyze the influencing factors of myopia. The prevalence of myopia was 23.10% at baseline in 2017, 28.67% after one year's follow-up and 33.26% after two years' follow-up among primary school students in grade one to grade three in Hubei province. The overall prevalence of myopia increased with time (χ²307.47, <0.05). It also increased with the increase of grades. After two years of follow-up, the myopia rate of students in grades one through three was 25.62%, 35.07% and 41.05%, respectively (χ²200.98, <0.05). In 2017, the prevalence of myopia was 21.62% in boys and 24.93% in girls, and it increased to 31.20% and 35.69% after 2 years of follow-up, respectively. Both the prevalence of myopia and the spherical equivalent refraction were higher in girls than in boys. Moreover, myopia was associated with parents' myopia (=1.17), less time for outdoor activities (=1.06), no rest after half an hour's study (=1.18), more time for daily exposure to electronic products (=1.07), longer time for extracurricular study (=1.09), and higher grades (=1.78). Children whose parents were more myopic and who ate sweets and fizzy drinks more often had greater levels of myopia. Myopia occurs early in primary school students of grade one to grade three in Hubei province and increases rapidly. More attention should be paid to good habits for eyes, regular screening, outdoor activities and girls. .