Table 3.

Zero-inflated negative binomial regression analysis, adjusted for an excess of zero values for associations between investigated variables; dependent variable: PGSI.

Model I. Analysis of the chance of not becoming susceptible to developing gambling problems.a
	OR	p	95% CI
Age	0.48	0.001	0.30	0.75
ADHD symptoms index	0.95	0.041	0.90	1.00
Gambling frequency index	0.46	0.009	0.26	0.82
ADHD symptoms × Gambling frequency index	0.92	0.023	0.85	0.99
Model II. Analysis of adolescents already susceptible to problem gambling.b
	IRR	p	95% CI
ADHD symptoms index	1.03	0.031	1.003	1.07
Gambling frequency index	1.34	<0.001	1.20	1.51
Sex (ref: boys)	0.25	<0.001	0.16	0.38
Sex × Gambling frequency index	1.67	<0.001	1.34	2.13

^aModel I: adjusted for covariates sex and parents’ country of birth.

^bModel II: adjusted for covariate age.