Table 3.

Associations of SAPS scores (PSU symptoms) and high smartphone usage time (> 2 h/d) with SDQ scores (behavioural difficulties) (N = 564)

behavioural difficulties represented by SDQ Scores
		prosocial behaviour	hyperactivity	emotional problems	conduct problems	peer relationship problems
Mean (sd)		7.83 (1.74)	3.50 (2.12)	2.30 (2.21)	1.71 (1.38)	2.14 (1.68)
Simple Regression
SAPS score (PSU symptoms)	b	-0.05	0.11	0.11	0.06	0.03
	CI 95%	-0.07—-0.03	0.09 – 0.14	0.08 – 0.13	0.05 – 0.08	0.01 – 0.05
	ß	-0.19	0.36	0.33	0.31	0.11
	t	-4.59	8.99	8.67	7.68	2.71
	p	< .001	< .001	< .001	< .001	0.007
	R2	0.10	0.15	0.22	0.14	0.04
	F	< .001	< .001	< .001	< .001	< .001
high smartphone usage time (> 2 h/d)	b	-0.19	0.39	0.41	0.41	0.19
	CI 95%	-0.51 – 0.12	-0.001 – 0.78	0.02 – 0.80	0.16 – 0.66	-0.12 – 0.50
	ß	-0.05	0.09	0.09	0.14	0.05
	t	-1.21	1.96	2.08	3.19	1.19
	p	0.22	0.05	0.04	0.001	0.23
	R2	0.07	0.04	0.12	0.06	0.03
	F	< .001	< .001	< .001	< .001	0.004
Multiple Regression
SAPS score (PSU symptoms)	b	-0.05	0.11	0.11	0.06	0.03
	CI 95%	-0.07—-0.03	0.09 – 0.14	0.08 – 0.13	0.04 – 0.08	0.01 – 0.05
	ß	-0.18	0.35	0.33	0.29	0.11
	t	-4.43	8.75	8.40	7.20	2.53
	p	< .001	< .001	< .001	< .001	0.01
high smartphone usage time (> 2 h/d)	b	-0.06	0.07	0.11	0.23	0.11
	CI 95%	-0.38 – 0.26	-0.30 – 0.44	-0.27 – 0.48	-0.01 – 0.48	-0.20 – 0.43
	ß	-0.02	0.01	0.02	0.08	0.03
	t	-0.36	0.37	0.56	1.89	0.69
	p	0.71	0.71	0.57	0.06	0.49
	R2	0.10	0.16	0.22	0.14	0.04
	F	< .001	< .001	< .001	< .001	< .001

All associations are adjusted for gender, age, SES, b non-standardized regression coefficient, ß standardized regression coefficient. Significant associations are highlighted in bold