Table 4.

Adjusted odds ratios of alcohol use and crash involvement between classes of substance users

			MJ/AMP	BZ/ANT	OPD/BZ	MJ/CN
Referent	No drug	One drug	class	class	class	class
Outcome: BrAC > .00 g/dl
No drug	–	1.86***	2.27*	4.30**	4.93***	1.91*
One drug		. –	1.29	2.30	2.47**	1.05
MJ/AMP class			.–	1.21	2.35*	0.81
BZ/ANT class				.–	1.02	0.29*
OPD/BZ class					.–	0.41*
MJ/CN class						.–
Outcome: Crash involvement
No drug	–	1.07*	1.08	0.79	1.69*	1.44*
One drug		. –	0.93	0.87	1.84**	1.46*
MJ/AMP class			.–	1.16	2.02*	1.36
BZ/ANT class				.–	2.18*	1.57
OPD/BZ class					.–	0.68*
MJ/CN class						.–

Notes: MJ/AMP = marijuana and amphetamine class; BZ/ANT = benzodiazepine and antidepressant class; OPD/BZ = opioid and benzodiazepine class; MJ/CN = marijuana and cocaine class; BrAC = breath alcohol concentration.

^*p < .05; **p < .01; ***p < .001.