Table 1.

Characteristics of the participants by sex

Characteristics	Total (n = 3,136)	Male (n = 1,507)	Female (n = 1,629)	P-value*	Effect size
Background variables
Age (years), mean (SD)	13.6 (1.3)	13.7 (1.3)	13.6 (1.3)	0.241	Cohen's d = 0.03
Born in Hong Kong
No	17.0%	16.1%	17.8%	0.186
Yes	83.0%	83.9%	82.2%		Odds ratio = 1.14
Living arrangement with parents
Both	73.0%	73.6%	72.5%	0.241
Mother	16.1%	15.6%	16.6%		Odds ratio = 0.93
Father	5.3%	5.9%	4.8%		Odds ratio = 1.20
Neither	5.5%	4.9%	6.1%		Odds ratio = 0.79
Mother's educational level
Primary school or below	7.4%	7.4%	7.3%	0.269
Middle school	45.3%	43.7%	46.8%		Odds ratio = 0.92
College or undergraduate	13.3%	13.4%	13.2%		Odds ratio = 0.99
Master or above	2.5%	3.0%	2.1%		Odds ratio = 1.44
Don't know	31.5%	32.4%	30.7%		Odds ratio = 1.04
Father's educational level
Primary school or below	10.1%	10.3%	10.0%	0.013
Middle school	46.9%	43.7%	49.8%		Odds ratio = 0.86
College or undergraduate	11.9%	13.0%	10.9%		Odds ratio = 1.17
Master or above	1.5%	1.5%	1.6%		Odds ratio = 0.92
Don't know	29.5%	31.5%	27.7%		Odds ratio = 1.11
Psychosocial variables, mean (SD)
COVID-19 stress	6.4 (1.7)	6.3 (1.8)	6.6 (1.4)	<0.001	Cohen's d = -0.15
Social support	21.6 (8.9)	21.3 (9.1)	22.0 (8.7)	0.034	Cohen's d = -0.08
Academic stress	18.1 (4.0)	17.7 (4.2)	18.6 (3.7)	<0.001	Cohen's d = -0.23
Maladaptive emotion regulation	9.7 (2.2)	9.5 (2.2)	9.8 (2.2)	<0.001	Cohen's d = -0.13
Depression
Total score	19.9 (11.2)	18.1 (10.7)	21.6 (11.4)	<0.001	Cohen's d = -0.32
Prevalence (yes, %)	60.3%	54.3%	65.8%	<0.001	Odds ratio = 0.62
Internet gaming disorder
Total score	2.1 (2.2)	2.5 (2.3)	1.7 (2.1)	<0.001	Cohen's d = 0.39
Prevalence (yes, %)	14.8%	19.6%	10.4%	<0.001	Odds ratio = 2.11

^* P-value is the test for differences between males and females. Note: Effect size of between-group comparison was presented using Cohen's d for continuous variables and odds ratio for categorical variables.