Objective: To investigate the distribution characteristics of myopia among primary and secondary school students in Inner Mongolia Autonomous Region in 2020, and to comprehensively analyze its influencing factors at both school and individual levels, thereby providing scientific evidence for developing targeted myopia prevention and control strategies.
Methods: A multistage stratified random cluster sampling method was employed to conduct vision examinations and questionnaire surveys among students from fourth grade to senior high school in Inner Mongolia Autonomous Region, collecting information on students' visual habits, school and family environmental factors. A multilevel regression model was used to analyze the factors influencing myopia detection rates at both school and individual levels.
Results: A total of 130 601 students were included, with a myopia prevalence rate of 68.42%. The prevalence was higher among females (72.75%) than males (64.13%), in urban areas (73.63%) than in suburban counties (66.38%), and overall rates increased with educational level (trend test χ2=4 545.53, P < 0.001). Multilevel analysis revealed that at the individual level, female gender (OR=1.553), higher grade level (junior high OR=2.049, senior high OR=3.061), homework duration ≥1 h after school (≥1 h OR=1.050, ≥2 h OR=1.079), poor close-up vision habits (OR=1.059), prolonged close-up vision activities (0.5 h OR=1.070, ≥1 h OR=1.061), infrequent desk/chair height adjustments based on height (OR=1.006), and parental myopia (one parent OR=1.822, both parents OR=2.412) were risk factors for myopia; while ethnic minority status (Mongolian OR=0.956, other ethnicities OR=0.929), daily outdoor activity exceeding 2 hours (OR=0.986), performing eye exercises (1 session OR=0.891, ≥2 sessions OR=0.920), and adequate sleep (OR=0.925) served as protective factors. At the school level, qualified blackboard reflectance ratio (OR=0.874) and qualified blackboard surface illuminance uniformity (OR=0.973) were associated with reduced myopia risk among students. The model indicated that the included variables collectively explained approximately 31.04% of the variance at the school level.
Conclusion: The prevalence of myopia among primary and secondary school students in Inner Mongolia Autonomous Region remains high, with influencing factors distributed across multiple levels including individual and school contexts. Comprehensive prevention strategies are recommended, focusing on female students, older grades, and those with genetic predispositions while intensifying interventions on modifiable factors like outdoor activities and visual habits. Improving classroom lighting environments is also crucial to reduce students' myopia risk.
目的: 了解2022年内蒙古自治区中小学生近视分布特征，并从学校与个体两个层面综合分析其影响因素，为制定有针对性的近视防控策略提供科学依据。
方法: 采用多阶段分层随机整群抽样方法，对内蒙古自治区四年级至高中三年级学生进行视力检查和问卷调查，收集学生用眼习惯、学校及家庭环境因素等信息。运用多水平回归模型分析近视检出率在学校和个体层面的影响因素。
结果: 调查共纳入中小学生130 601例，近视检出率为68.42%，其中女生近视检出率(72.75%)高于男生(64.13%)，城区近视检出率(73.63%)高于郊县(66.38%)，整体随学段的增加呈上升趋势(趋势检验χ2=4 545.53，P＜0.001)。多水平分析结果显示，在个人层面，女生(OR= 1.553)、高年级学生(初中OR=2.049，高中OR=3.061)、放学后作业时长≥1 h(≥1 h OR=1.050, ≥2 h OR=1.079)、近距离用眼习惯不良(OR=1.059)、长时间近距离用眼(0.5 h OR=1.070，≥1 h OR=1.061)、课桌椅高度根据身高调整周期长(OR=1.006)、父母近视(仅一方近视OR=1.822，均近视OR=2.412)是近视的危险因素；少数民族(蒙古族OR=0.956，其他民族OR=0.929)、每天户外活动时间超过2 h(OR=0.986)、做眼保健操(1次OR=0.891，≥2次OR=0.920)、睡眠充足(OR=0.925)为保护因素。在学校层面，黑板反射比合格(OR=0.874)与黑板面照度均匀度合格(OR=0.973)与学生近视风险降低有关。模型显示，所纳入的变量共同解释了约31.04%的学校水平方差。
结论: 内蒙古自治区中小学生近视检出率处于较高水平，且影响因素分布于个体和学校多个层面；建议采取综合防控策略，在重点关注女生、高年级及有遗传背景学生的同时，加强对户外活动、用眼行为等可改变因素的干预，并改善教室光环境，以降低学生近视发生风险。
Keywords: Influencing factors; Multilevel model; Myopia; Primary and secondary school students.