Table 3.

Bootstrap confidence interval (CI) and effect size of the mediation model.

Mediation paths	Total sample			Early adolescence			Middle adolescence			Late adolescence
	Estimate	95% CI	PM	Estimate	95% CI	PM	Estimate	95% CI	PM	Estimate	95% CI	PM
PIU→Dep→AE	−0.21	[−0.24, −0.19]	0.48	−0.13	[−0.16, −0.09]	0.31	−0.25	[−0.29, −0.21]	0.59	−0.22	[−0.27, −0.18]	0.49
PIU→Anx→AE	0.09	[0.06, 0.12]	−	0.04	[0.01, 0.07]	−	0.11	[0.06, 0.16]	−	0.10	[0.06, 0.14]	−
PIU→Ins→AE	−0.02	[−0.03, −0.01]	0.05	−0.01	[−0.02, −0.003]	0.03	−0.02	[−0.04, −0.01]	0.06	−0.02	[−0.03, −0.01]	0.04
PIU→Dep→Ins→AE	−0.02	[−0.02, −0.01]	0.03	−0.004	[−0.01, 0.00]	0.01	−0.02	[−0.03, −0.01]	0.05	−0.02	[−0.03, −0.01]	0.05
PIU→Anx→Ins→AE	−0.02	[−0.02, −0.01]	0.04	−0.01	[−0.02, −0.003]	0.03	−0.02	[−0.03, −0.01]	0.05	−0.02	[−0.03, −0.01]	0.04

Note. PIU = Problematic Internet Use; Dep = Depression; Anx = Anxiety; Ins = Insomnia; AE = Academic Engagement.

P_M = ratio of the indirect effect to the total effect. Mediation path PIU→Anx→AE is an inconsistent mediation model without P_M.