Table 5.
The proportion of sex disparity in myopia explained by puberty and behavioral factors, in boys and girls 11 to 18 years of age in the 2014 CNSSCH. sample size = 125,466).
| Sex (girls vs. boys) | PERM | |||
|---|---|---|---|---|
| β | PR (95%CI) | P | ||
| Unadjusted model | 0.11 | 1.118 (1.105, 1.132) | <0.001 | NA |
| Basic model 1 | 0.12 | 1.122 (1.110, 1.135) | <0.001 | NA |
| Additionally adjusted models | ||||
| Puberty | 0.10 | 1.102 (1.090, 1.114) | <0.001 | 16.71% |
| Weekend outdoor activity | 0.12 | 1.122 (1.109, 1.134) | <0.001 | 0.61% |
| Weekend study activity | 0.11 | 1.116 (1.105, 1.129) | <0.001 | 4.78% |
| Physical activity time per day | 0.11 | 1.121 (1.109, 1.134) | <0.001 | 0.94% |
| Homework time per day | 0.11 | 1.117 (1.105, 1.129) | <0.001 | 4.30% |
| Self-report study pressure | 0.12 | 1.122 (1.110, 1.135) | <0.001 | 0.19% |
| Near screen time per day | 0.11 | 1.120 (1.108, 1.133) | <0.001 | 1.68% |
| Sleep duration per day | 0.11 | 1.121 (1.108, 1.133) | <0.001 | 1.41% |
| All seven behavioral factors (Basic model 2) | 0.10 | 1.109 (1.097, 1.120) | <0.001 | 11.14% |
| Basic model 2 + puberty | 0.09 | 1.090 (1.079, 1.102) | <0.001 | 16.75% |
PR, prevalence ratio. PERM, percentage of excess risk mediated. NA, not applicable. In the basic model, we adjusted for exact age, urban–rural location, regional SES within province, fixed effect of province, and the cluster effect of school.