Myopigenic Activity Change and Its Risk Factors in Urban Students in Beijing: Three-Year Report of Beijing Myopia Progression Study.
PURPOSE
To investigate the myopigenic activity change and its risk factors in urban students in Beijing.


METHODS
A total of 241 primary or secondary students aged 6-17 years from the Beijing Myopia Progression Study (BMPS) were re-examined 3 years after their baseline enrollment. A detailed questionnaire was administered to assess myopigenic activities at both baseline and at the 3-year follow-up. Altogether, 217 students (90.0%) with completed data were included in the analysis.


RESULTS
Compared to baseline, primary students (n = 123) had significant increases in outdoor sports time (mean ± standard deviation: 3.5 ± 4.3 vs. 2.4 ± 3.0 hours/week, p = 0.02), near work time (32.1 ± 13.4 vs. 24.8 ± 9.2 hours/week, p < 0.001), diopter hours (128.8 ± 53.3 vs. 97.5 ± 35.9 diopter hours/week, p < 0.001), and indoor time (53.8 ± 22.8 vs. 41.4 ± 16.9 hours/week, p < 0.001) at the 3-year follow-up. At both baseline and follow-up, females spent less time than males on outdoor sports (baseline: 2.4 ± 2.8 vs. 4.0 ± 5.2 hours/week, p = 0.006; follow-up: 2.3 ± 3.1 vs. 5.1 ± 5.0 hours/week, p < 0.001), and total outdoors (baseline: 11.9 ± 7.9 vs. 14.4 ± 9.5 hours/week, p = 0.03; follow-up: 10.5 ± 8.2 vs. 13.9 ± 9.6 hours/week, p = 0.005). In the multivariate regression analysis after adjustment by student's gender, younger students had more increase in both near work time (slope = -0.99 hours/week for age, p = 0.009) and indoor time (slope = -2.04 hours/week for age, p = 0.001).


CONCLUSIONS
During the 3-year follow-up, primary students had more myopigenic activities. Female students had more myopigenic activities than males at both baseline and follow-up. Children's age was a significant risk factor for this myopigenic activity change.
['Lin|Zhong|Z|', 'Vasudevan|Balamurali|B|', 'Ciuffreda|Kenneth J|KJ|', 'Zhou|Hong Jia|HJ|', 'Mao|Guang Yun|GY|', 'Wang|Ning Li|NL|', 'Liang|Yuan Bo|YB|']
D000293:Adolescent D000068476:Beijing D002648:Child D018450:Disease Progression D005260:Female D005500:Follow-Up Studies D006801:Humans D015994:Incidence D008297:Male D009216:Myopia D012029:Refraction, Ocular D012189:Retrospective Studies D018570:Risk Assessment D012307:Risk Factors D013334:Students D011795:Surveys and Questionnaires D013997:Time Factors D014505:Urban Population
myopigenic activity risk factors Myopia near work outdoor activity