Table 2.

Variables associated with the alteration of sleep duration based on Generalized Estimating Equations (N = 2496).

Variables	β	SE	Wald χ2	P	OR
Gender = girl	−0.021	0.039	0.294	0.588	0.979
Infection history = yes	−2.480	0.132	353.917	<0.001	0.084
Nationality = Minority	0.212	0.219	0.943	0.331	1.236
Dwelling = suburban	0.052	0.040	1.678	0.195	1.054
Only child = yes	0.023	0.043	0.289	0.591	1.024
Time point = Wave 2	−0.323	0.027	146.133	<0.001	0.724
Grade
9	−0.333	0.100	11.204	0.001	0.717
8	−0.212	0.061	12.008	0.001	0.809
7	–	–	–	–	–
Age	0.043	0.036	1.479	0.224	1.044
CES-DC score	−0.006	0.002	10.533	0.001	0.994
Exercise duration	0.067	0.029	5.250	0.022	1.069