Table 3.

Negative binomial models predicting frequency of e-cigarette and hookah use.

Predictor	Coefficient	Standard Error	z-score	p-value
E-cigarettes: model χ2 (6) = 46.73, p < .001
Age	−0.02	0.08	−0.31	.758
Sex	−0.52	0.22	−2.32	.020
Race/ethnicity	0.04	0.12	0.35	.729
Student status	−0.14	0.27	−0.50	.615
Cigarette days	−0.01	0.03	−0.25	.800
E-cigarette expectancies	1.38	0.23	6.04	<.001
Hookah: model χ2 (6) = 34.89, p < .001
Age	−0.02	0.07	−0.24	.809
Sex	−0.32	0.24	−1.36	.175
Race/ethnicity	0.10	0.11	0.89	.375
Student status	0.24	0.25	0.96	.336
Cigarette days	0.11	0.03	3.94	<.001
Hookah expectancies	0.78	0.17	4.66	<.001