Table 2.

ITT regression analyses

	Coefficient	Standard error	t	p	95% CI
Primary outcome
IUD criteria
Time: Follow-up 1 (T1)	−0.48	0.13	−3.61	0.000	−0.74; −0.21
Time: Follow-up 2 (T2)	−0.64	0.13	−4.88	0.000	−0.90; −0.38
Intervention* Time: Follow-up 1 (T1)	−0.13	0.17	−0.78	0.433	−0.47; 0.20
Intervention* Time: Follow-up 2 (T2)	−0.30	0.20	−1.45	0.149	−0.71; 0.11
Secondary outcomes
Readiness to change
Time: Follow-up 1 (T1)	−0.31	0.08	−3.87	0.000	−0.47; −0.15
Time: Follow-up 2 (T2)	−0.68	0.13	−5.15	0.000	−0.94; −0.42
Intervention* Time: Follow-up 1 (T1)	0.09	0.11	0.81	0.420	−0.13; 0.32
Intervention* Time: Follow-up 2 (T2)	−0.21	0.21	−1.00	0.317	−0.63; 0.20
Self-efficacy to change
Time: Follow-up 1 (T1)	0.11	0.08	0.13	0.190	−0.06; 0.29
Time: Follow-up 2 (T2)	−0.64	0.17	−3.84	0.000	−0.96; −0.31
Intervention* Time: Follow-up 1 (T1)	−0.01	0.12	−0.16	0.876	−0.26; 0.22
Intervention* Time: Follow-up 2 (T2)	0.21	0.24	0.86	0.393	−0.27; 0.68
Impairments
Time: Follow-up 1 (T1)	0.37	0.11	3.39	0.001	0.16; 0.59
Time: Follow-up 2 (T2)	0.74	0.22	3.34	0.001	0.31; 1.18
Intervention* Time: Follow-up 1 (T1)	0.13	0.15	0.83	0.407	−0.17; 0.43
Intervention* Time: Follow-up 2 (T2)	0.26	0.32	0.83	0.408	−0.36; 0.88

Notes: ITT = Intention-to-Treat, IUD = Internet use disorders, Time T1 = Follow-up after five months; T2 = Follow-up after ten months; CI = confidence interval. The analysis was adjusted for age, sex, migration background, self-efficacy to change, readiness to change, and the baseline score of each outcome.