Table 2.

Univariate logistic regression analysis on the associations between the studied background variables and internet gaming disorder (N=3081).

Background variables		IGDa, n (%)		Association, ORcb (95% CI)
Sex
	Femalec	119 (7.8)	N/Ad
	Male	297 (19.16)	2.80 (2.23-3.51)***
Grade
	Sevenc	226 (11.42)	N/A
	Eight	114 (19.69)	1.90 (1.49-2.44)***
	Nine	78 (14.91)	1.36 (1.03-1.80)*
Study site
	Guangzhouc	96 (8.53)	N/A
	Chengdu	322 (16.47)	2.12 (1.66-2.69)***
Born in the city where the study was conductede
	Yesc	308 (13.01)	N/A
	No	105 (15.2)	1.20 (0.94-1.52)
Living with both parentse
	Yesc	294 (12.34)
	No	114 (17.84)	1.54 (1.22-1.95)***
Father’s educational levele
	Junior middle school or belowc	227 (15.25)	N/A
	Senior middle school or equal	109 (13.12)	0.84 (0.66-1.07)
	College or above	52 (8.75)	0.53 (0.39-0.73)***
Mother’s educational levele
	Junior middle school or belowc	218 (14.23)	N/A
	Senior middle school or equal	102 (12.7)	0.88 (0.68-1.13)
	College or above	60 (10.6)	0.72 (0.53-0.97)*
Household income level when compared with classmatese
	Much higher/higherc	87 (12.95)	N/A
	Moderate	246 (12.29)	0.94 (0.73-1.22)
	Lower/much lower	76 (19.64)	1.64 (1.17-2.30)**
Self-reported academic performancee
	Above averagec	98 (9.61)	N/A
	Average	169 (12.54)	1.35 (1.04-1.76)*
	Below average	127 (21.17)	2.53 (1.90-3.36)***

^aIGD: internet gaming disorder.

^bORc: crude odds ratio.

^cReference=1.0

^dN/A: not applicable.

^eMissing data were excluded from the analysis.

*P<.05.

**P<.01.

***P<.001.