Table 6.

Logistic regression analyses comparing respondents (N = 839) reporting past 12-month use of cocaine only (n = 144), opioids only (n = 622) or both (n = 73) with regard to diagnosis of current (past-12-month) DSM-IV alcohol use disorder, nicotine dependence and other substance use disorders.

	Alcohol Use Disorder			Nicotine Dependence			Other Substance Use Disorder
Variable	O.R.	95% C.I. for O.R.	p-val	O.R.	95% C.I. for O.R.	p-val	O.R.	95% C.I for O.R.	p-val
Family history	1.44	0.93–2.23	.100	1.31	0.90–1.90	.156	2.02	1.32–3.09	.001
Cocaine use only	0.85	0.39–1.85	.679	0.50	0.26–0.96	.039	0.85	0.41–1.74	.648
Opioid use only	0.37	0.19–0.73	.004	0.58	0.32–1.03	.064	0.33	0.17–0.61	<.001

Notes: Other substance use disorder included diagnosis of current (past-12-month) abuse or dependence for sedatives, tranquilizers, cannabis, inhalants, hallucinogens, amphetamines or other drugs. Cocaine use only and opioid use only were dummy codes with cocaine/opioid co-use as the reference group. Family history was coded 1 for at least 1 first order relative with a history of a drug problem and 0 for no first order relative with a history of a drug problem In each model, the following variables were held constant: sex, marital status (currently married or unmarried), military status, educational attainment (at least some college or not), race/ethnicity (White or Non-White) and age. Full results including findings for these covariates are available from the authors. O.R.: odds ratio, C.I.: confidence interval