Document resource
Objective The development of myopia is subject to individual genetic predisposition and environmental risk exposures. This study aims to investigate the trajectories and predictors of spherical equivalent (SE) among multiethnic school-aged children in Southwest China.Methods The school-based cohort study was conducted from October 2020 to March 2023 in Yunnan province, Southwest China. Ocular examinations and questionnaire surveys were administered at each visit. A total of 679 students with complete records from all three visits were included in the final analyses. Group-based trajectory modelling was used to identify SE trajectories. Associations between the trajectory groups and baseline predictors were assessed using multinomial logistic regression.Results We identified two distinct trajectory groups of SE in grades 2–3: slow progressive (84.4% of students) and rapid progressive (15.6%). Multivariate analysis indicated that children with myopic parents and those who often stayed in the classrooms during recess were more likely to belong to the rapid progressive group. By contrast, three trajectory groups of SE were identified in grade 7: slow progressive (52.3% of students), moderate initial and rapid progressive (33%) and low initial and rapid progressive (14.7%). In multivariate models, being a girl, having myopic parents, using mobile screens for more than 0.5 hours per day and often staying in the classrooms during recess were predictors of the progressive groups. Moreover, there were no significant differences in SE trajectories between Han and ethnic groups.Conclusion There is heterogeneity in the developmental trajectories of SE, for both primary and secondary school students. Tailored intervention strategies based on the predictors of the SE trajectories should be under special consideration.