. 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 5.

Multiple regression predicting exit 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)	8.79	.82		10.72^**	6.71	.93		7.19^**	6.25	.93		6.69^**	1.76	.95		1.86
Age	−0.08	.02	−0.11	−3.45^**	−0.06	.02	−0.08	−2.61^**	−0.06	.02	−.09	−2.75^**	−0.02	.02	−.02	−0.80
Gender (female referent)	−0.12	.28	−0.01	−0.40	−0.27	.28	−0.03	−0.95	−0.38	.28	−.04	−1.34	−0.19	.27	−.02	−0.70
Sexual orientation (Heterosexual referent)	1.43	.31	0.12	4.62^**	1.42	.31	0.12	4.63^**	1.38	.31	.12	4.52^**	1.12	.29	.10	3.86^**
Race (white referent)	−1.48	.33	−0.13	−4.53^**	−1.31	.33	−0.12	−3.99^**	−1.28	.33	−.12	−3.93	−1.12	.31	−.10	−3.63^**
Ethnicity (hispanic referent)	−1.05	.36	−0.09	−2.91^**	−1.05	.36	−0.09	−2.95^**	−1.02	.35	−.08	−2.87	−0.87	.34	−.07	−2.60^**
Student Status (Non-student referent)	−0.69	.34	−0.06	−2.02^*	−0.65	.34	−0.06	−1.93	−0.55	.33	−.05	−1.64	−0.28	.32	−.03	−0.87
Employment status (full-time referent)	−0.08	.35	−0.01	−0.23	−0.07	.34	−0.01	−0.22	−0.12	.34	−.01	−0.34	0.13	.32	−.01	−0.39
Education level (less than college referent)	0.61	.31	0.06	1.97^*	0.53	.31	0.05	1.72	0.68	.31	.06	2.20^*	0.53	.29	.05	1.84
Income	0.02	.01	0.08	2.17^*	0.02	.01	0.08	2.27^*	0.02	.01	.08	2.40^*	0.02	.01	.09	2.69^**
Marital status (single referent)	−0.71	.37	−0.06	−1.90	−0.73	.37	−0.06	−2.00^*	−0.65	.37	−.05	−1.78	−0.48	.35	−.04	−1.37
Relationship status (no relationship referent)	−0.27	.32	−0.02	−0.84	−0.28	.32	−0.02	−0.89	−0.18	.32	−.02	−0.56	−0.31	.30	−.03	−1.05
Size of social group					0.29	.10	0.08	2.94^**	0.29	.10	.07	2.96^**	0.21	.09	.06	2.27^*
Concern about group safety					0.25	.29	0.02	0.84	0.26	.28	.02	0.90	0.40	.27	.04	1.49
Someone takes responsibility for safety (Yes referent)					−0.50	.32	−0.04	−1.56	−0.44	.32	−.04	−1.39	−0.08	.30	−.01	−0.27
Frequently drunk group member (no referent)					1.45	.24	0.16	6.02^**	1.42	.24	.16	5.93^**	1.19	.23	.13	5.26^**
Drug use									1.32	.32	.11	4.18^**	1.07	.30	.09	3.59^**
Passenger													3.88	.32	.36	12.32^**
Non-private transportation method													4.71	.45	.31	10.51^**
	R² = .05				R² = .08, ΔR² = .03,				R² = .09, ΔR² = .01,				R² = .20, ΔR² = .10,
	F(11,1399) = 6.52^**				F(4,1395) = 8.36^**				F(2,1394) = 9.02^**				F(2,1392) = 18.73^**

p < .05.

^**

p < .01.