Table 2. Screen time and behavioral problems in 2020 and 2021 (n = 186).

Variables		2020	2021	MD	T value	P value
Screen time variables
	Smartphone frequency per week	4.54	5.35	0.81	4.13	< 0.001
	Smartphone screen time per day	3.16	3.52	0.37	3.69	< 0.001
	Tablet PC frequency per week	3.44	3.77	0.34	1.41	0.160
	Tablet PC screen time per day	2.72	3.22	0.50	3.76	< 0.001
	TV frequency per week	4.77	3.77	−1.00	−5.43	< 0.001
	TV screen time per day	3.26	2.88	−0.39	−4.09	< 0.001
Children’s variables
	Sleep Problem Score (CSHQ)	3.67	3.59	0.75	0.47	0.641
	Problematic Behavior Score (BPI)	11.85	9.15	−2.71	−5.55	< 0.001
Parents’ variables
	Depression Score (PHQ-9)	5.06	5.59	0.53	1.62	0.106

CSHQ = Children’s Sleep Habits Questionnaire, BPI = Behavior Problem Index, PHQ-9 = Patient Health Questionnaire-9.