Table 2.

Multivariate logistic regression model for bedtime and baseline myopia.

Variable	Adjusted OR (95% CI)	Test statistic, p
Area: sub-urban	1 (Reference)
Urban	1.44 (1.12, 1.84)	z = 2.85, p = 0.004
Age (years): 6 years	1 (Reference)
7 years	3.02 (2.21, 4.14)	z = 6.91, p < 0.001
8 years	4.08 (2.89, 5.75)	z = 8.00, p < 0.001
Gender: Male	1 (Reference)
Female	0.77 (0.62, 0.95)	z = − 2.42, p = 0.02
Usual bedtime: Before 9 p.m.	1 (Reference)
9 to 9:29 p.m.	1.38 (0.99, 1.94)	z = 1.88, p = 0.06
9:30 p.m. and after	1.55 (1.02, 2.34)	z = 2.06, p = 0.04
Sleep duration (h): < 9.5 h	1 (Reference)
9.5 to 10 h	1.07 (0.83, 1.39)	z = 0.53, p = 0.60
10 h and more	1.23 (0.88, 1.72)	z = 1.22, p = 0.22
Outdoor weekly total (per h)	0.96 (0.93, 0.98)	z = − 3.13, p = 0.002