Table 5a.

Covariates associated with opioid-free time, defined as lack of opioids in the urine in the last month of observed treatment

Covariates	Opioid negative urine samples in last month of BMT
	Univariate Analysis			Multivariate Analysis
	Logistic Regression			Logistic Regression
	OR	95% CI	P value	AOR	95% CI	P value
Age	1.01	(0.98, 1.03)	0.46
Gender
Male	Ref
Female	1.21	(0.70, 2.07)	0.49
Site
Site 1	Ref
Site 2	0.98	(0.59, 1.60)	0.94
Specialty
Psychiatry	Ref
Primary Care Provider	0.64	(0.36, 1.10)	0.11	*
Baseline Cocaine Screen
Negative	Ref
Positive	0.52	(0.29, 0.92)	0.03
Any Cocaine Screen
Negative	Ref			Ref
Positive	0.43	(0.25, 0.72)	<0.01	0.43	(0.25, 0.73)	<0.01
Receipt of on-site substance abuse counseling
No	Ref
Yes	0.68	(0.41, 1.11)	0.13	*
Mood disorder
No	Ref
Yes	1.56	(0.88, 2.73)	0.12	*
Prescribed psychiatric medication
No	Ref			Ref
Yes	1.67	(0.98, 2.83)	0.06	1.66	(1.03, 2.85)	<0.01
HIV-infected
No	Ref
Yes	0.87	(0.38, 1.98)	0.75
HCV-infected
No	Ref
Yes	0.87	(0.52, 1.45)	0.60
AIC Goodness of Fit					356

^*Non-significant variables were excluded by AIC/criteria in the multivariate model

BMT = buprenorphine maintenance therapy; Ref = referent; AIC = Akaike Information Criterion; GLM=Generalized Linear Model; OLS= Ordinary Least Square Regression