Table 5.

Linear 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 past-12-month alcohol use

	Drinks per drinking day			Peak number of drinks in a day
Variable	beta	S.E.	p-val	beta	S.E.	p-val
Family history	0.07	0.03	.01	0.10	0.03	.001
Cocaine use only	−0.02	0.05	.730	−0.07	0.06	.241
Opioid use only	−0.11	0.04	.009	−0.18	0.05	.001

Notes: Both alcohol variables winsorized, then log transformed to reduce skew. 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.