Table 2.

Structural equation model of the effects of the frequency of social media use and problematic social media use separately and jointly on bedtime and perceived quality of sleep.

	Bedtime T2		Quality of Sleep T2
Frequency of Social Media Use	β	SE	β	SE
Gender (ref = girls)	0.09 **	0.02	0.04	0.02
Age	0.15 **	0.03	−0.08 *	0.03
Educational level (ref = higher)	−0.02	0.03	0.01	0.02
Bedtime T1	0.49 **	0.03	-	-
Quality of sleep T1	-	-	0.58 **	0.02
Frequency social media use T1	0.14 **	0.03	−0.04	0.02
Problematic Social Media Use	β	SE	β	SE
Gender (ref = girls)	0.07 **	0.02	0.04	0.02
Age	0.15 **	0.03	−0.08 *	0.03
Educational level (ref = higher)	−0.01	0.03	0.01	0.02
Bedtime T1	0.52 **	0.03	-	-
Quality of sleep T1	-	-	0.58 **	0.02
Problematic social media use T1	0.07 *	0.02	−0.03	0.02
Frequency of Social Media Use and Problematic Social Media Use	β	SE	β	SE
Gender (ref = girls)	0.09 **	0.02	0.04	0.02
Age	0.15 **	0.03	−0.08 *	0.03
Educational level (ref = higher)	−0.02	0.03	0.01	0.02
Bedtime T1	0.49 **	0.03	-	-
Quality of sleep T1	-	-	0.58 **	0.02
Frequency social media use T1	0.13 **	0.03	−0.03	0.02
Problematic social media use T1	0.04	0.03	−0.03	0.03

Note. β = standardized coefficient; SE = standard error. * p < 0.01. ** p < 0.001.