Table 4.

Multivariate logistic analysis of the risk factors for presence of RA and CA

Factors	RA				CA
	P value	OR	95% CI		P value	OR	95% CI
Mean corneal curvature (D)	< 0.001	1.24	1.188–1.295		< 0.001	1.286	1.239 − 1.334
Learning stages
kindergarten	Reference				Reference
Primary school	0.204	0.893	0.751–1.063		0.885	0.99	0.861 − 1.138
Junior high school	< 0.001	1.973	1.579–2.464		< 0.001	1.828	1.493 − 2.238
Spherical power (D)	0.021	0.956	0.921–0.993		0.744	1.006	0.971 − 1.042
Gender
Boy	Reference				Reference
Girl	< 0.001	0.698	0.617–0.790		0.283	1.059	0.954 − 1.177
Homework time on weekdays (hour/day)	0.029	1.074	1.007–1.145		0.06	1.062	0.997 − 1.130
Outdoor activity time on weekends (hour/day)	0.013	0.929	0.877–0.984		0.444	0.983	0.940 − 1.027
Watching TV within two meters
Almost none	Reference				Reference
Sometimes	0.126	1.103	0.973–1.250		0.427	1.044	0.938 − 1.162
Often	0.06	1.254	0.991–1.586		0.712	1.041	0.843 − 1.285
Homework time on weekends (hour/day)	0.666	1.01	0.967–1.054		0.808	0.995	0.955 − 1.037
Outdoor activity time on weekdays (hour/day)	0.971	1.002	0.904–1.111		0.815	1.01	0.926 − 1.103
Continuous near work for more than 30–40 min
Almost none	Reference				Reference		-
Sometimes	0.569	1.048	0.892–1.231		0.708	0.973	0.844 − 1.122
Often	0.235	0.892	0.74–1.077		0.448	0.94	0.803 − 1.102
Birth weight(g)	0.841	1	1.000–1.000		0.398	1	1.000 − 1.000
Preterm birth
No	Reference				Reference
Yes	0.642	1.066	0.814–1.396		0.77	1.037	0.813 − 1.322
Paternal myopia
No	Reference				Reference
Yes	0.05	1.137	1.000–1.293		0.62	0.973	0.872 − 1.085
Maternal myopia
No	Reference				Reference
Yes	0.271	1.076	0.945–1.225		0.566	1.033	0.925 − 1.154

RA, refractive astigmatism; CA, corneal astigmatism