. Author manuscript; available in PMC: 2016 Jul 1.

Published in final edited form as: Transp Res Part F Traffic Psychol Behav. 2015 Jul 1;32:11–22. doi: 10.1016/j.trf.2015.04.009

Table 3.

Multiple regression predicting entry BAC (demographics, group characteristics, drug use, transportation method).

N = 1414	Step 1				Step 2				Step 3				Step 4

	B	SE	β	t	B	SE	β	t	B	SE	β	t	B	SE	β	t
(Constant)	6.28	.64		9.80^**	4.30	.73		5.86^**	3.90	.73		5.32^**	1.65	.77		2.15
Age	−0.10	.02	−.18	−5.56^**	−0.09	.02	−.15	−4.69^**	−0.09	.02	−.02	−4.86^**	−.07	.02	−.11	−3.61^**
Gender (female referent)	0.20	.22	.02	0.87	0.09	.22	.01	0.42	−0.03	.22	.00	−0.02	0.08	.22	.01	0.35
Sexual orientation (heterosexual referent)	1.20	.24	.13	4.93^**	1.24	.24	.13	5.12^**	1.20	.24	.13	5.01^**	1.04	.24	.11	4.41^**
Race (white referent)	−1.45	.26	−.17	−5.65^**	−1.40	.26	−.16	−5.46^**	−1.39	.26	−.16	−5.42^**	−1.29	.25	−.15	−5.14^**
Ethnicity (hispanic referent)	−0.75	.28	−.08	−2.64^**	−0.76	.28	−.08	−2.71^**	−0.73	.28	−.08	−2.62^**	−0.65	.27	−.07	−2.40^*
Student status (non-student referent)	−0.32	.27	−.04	−1.18	−0.28	.26	−.03	−1.05	−0.19	.26	−.02	−0.71	−0.06	.26	−.01	−0.22
Employment status (full-time referent)	0.06	.27	.01	0.23	0.07	.27	.01	0.26	0.04	.27	.00	0.14	0.04	.26	.01	0.16
Education Level (less than college referent)	0.54	.24	.06	2.22^*	0.49	.24	.06	2.01^*	0.62	.24	.07	2.56^*	0.55	.24	.07	2.34^*
Income	0.02	.01	.11	3.18^**	0.02	.01	.12	3.35^**	0.02	.01	.12	3.50^**	0.02	.01	.12	3.65^**
Marital status (single referent)	−0.41	.29	−.04	−1.39	−0.44	.29	−.04	−1.52	−0.37	.29	−.04	−1.29	−0.28	.28	−.03	−1.01
Relationship status (no relationship referent)	−0.01	.25	−.00	−0.05	−0.02	.25	−.00	−0.06	0.08	.25	.01	0.31	0.01	.24	.00	0.03
Size of social group					0.28	.08	.10	3.64^**	0.28	.08	.10	3.67^**	0.25	.08	.08	3.27^**
Concern about group safety					0.37	.23	.04	1.63	0.38	.22	.05	1.70	0.46	.22	.05	2.09^*
Someone takes responsibility for safety (yes referent)					−0.11	.25	−.01	−0.44	−0.06	.25	−.01	−0.24	0.15	.25	.02	0.60
Frequently drunk group member (no referent)					0.97	.19	.13	5.13^**	0.95	.19	.13	5.04^**	0.83	.19	.11	4.47^**
Drug use									1.67	.25	.12	4.71^**	1.05	.24	.11	4.32^**
Passenger													1.83	.26	.21	7.13^**
Non-private transportation method													2.58	.37	.21	7.07^**
	R² = .07,				R² = .10, ΔR² = .03,				R² = .11, ΔR² = .01,				R² = .15, ΔR² = .04,
	F(11,1399) = 9.1^**				F(4,1395) = 10.0^**				F(1,1394) = 10.8^**				F(2,1392) = 13.7^**

p < .05.

^**

p< .01.