Table 1.

The correlation matrix between age, number of family members, time spent on the Internet on weekdays and holidays, sleep duration, total scores of IAT test, and total scores of K6 scale

		IAT total scores	K6 scale total scores	Number of family members	Age	Internet first exposure	Weekday Internet usage	Holiday Internet usage	Sleep duration
IAT total scores	ρ	1	0.476**	0.025	0.269**	−0.002	0.433**	0.458**	−0.244**
	P		<0.001	0.162	<0.001	0.927	<0.001	< 0.001	<0.001
K6 scale total scores	ρ	0.476**	1	0.038*	0.187**	−0.02	0.194**	0.179**	−0.123**
	P	<0.001		0.031	<0.001	0.259	<0.001	< 0.001	<0.001
Number of family	ρ	0.025	0.038*	1	0.122**	0.114**	0.052**	0.092**	−0.078**
members	P	0.162	0.031		<0.001	<0.001	0.003	<0.001	<0.001
Age	ρ	0.269**	0.187**	0.122**	1	0.265**	0.449**	0.369**	−0.336**
	P	<0.001	<0.001	<0.001		<0.001	<0.001	<0.001	<0.001
Internet first	ρ	−0.002	−0.02	0.114**	0.265**	1	0.081**	0.075**	−0.114**
exposure	P	0.927	0.259	<0.001	<0.001		<0.001	<0.001	<0.001
Weekday Internet	ρ	0.433**	0.194**	0.052**	0.449**	0.081**	1	0.800**	−0.269**
usage	P	<0.001	<0.001	0.003	<0.001	<0.001		<0.001	<0.001
Holiday Internet	ρ	0.458**	0.179**	0.092**	0.369**	0.075**	0.800**	1	−0.261**
usage	P	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001		<0.001
Sleep duration	ρ	−0.244**	−0.123**	−0.078**	−0.336**	−0.114**	−0.269**	−0.261**	1
	P	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

Notes: ρ: Spearman’s rank correlation coefficient, p: P-value.

^*P<0.05,

^**P<0.01.

Abbreviation: IAT, Internet addiction test.