[The relationship between migration time and the prevalence of myopia of children and adolescents aged 6-18 years old in Shenzhen].

Objective: To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen. Methods: From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin'an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ2 test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results: The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [OR (95%CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [OR (95%CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [OR (95%CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion: The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.