Table 3.

Covariates associated with non-retention on buprenorphine maintenance therapy^#

Covariates	6-Month Non-Retention						12-Month Non-Retention
	N=266						N=136
	Unadjusted HR			Adjusted HR			Unadjusted HR			Adjusted HR
	H.R.	95% CI	P value	H.R.	95% CI	P value	H.R.	95% CI	P value	H.R.	95% CI	P value
Age	0.96	(0.94, 0.98)	<0.01	0.96	(0.94, 0.98)	<0.01	0.99	(0.96, 1.02)	0.62
Gender
Male	Ref			Ref
Female	0.76	(0.49, 1.1)	0.19	0.59	(0.37, 0.92)	0.02	0.69	(0.36, 1.3)	0.26
Site
Site 1	Ref
Site 2	0.80	(0.54, 1.20)	0.22				0.78	(0.45, 1.4)	0.39
Prescriber Specialty
Psychiatry	Ref
Primary Care	0.85	(0.79, 1.72)	0.45				0.67	(0.85, 2.59)	0.16	*
Baseline Cocaine Screen
Negative	Ref			Ref			Ref			Ref
Positive	1.73	(1.18, 2.54)	0.01	2.18	(1.35, 3.50)	<0.01	2.06	(1.20, 3.51)	<0.01	3.12	(1.57, 6.16)	<0.01
Any Cocaine Screen
Negative	Ref
Positive	1.36	(0.94, 1.97)	0.10	*			1.22	(0.73, 2.04)	0.44
Mood Disorder
No	Ref						Ref
Yes	1.06	(0.81, 1.40)	0.65				1.08	(0.73, 1.59)	0.68
Prescribed psychiatric medication
No	Ref			Ref			Ref			Ref
Yes	0.57	(1.2, 2.6)	<0.01	0.69	(0.47, 1.01)	0.05	0.41	(0.24, 0.69)	<0.01	0.36	(0.20, 0.62)	<0.01
HIV-infected
No	Ref						Ref
Yes	1.16	(0.56, 1.8)	0.98				1.39	(0.66, 2.94)	0.38
HCV-infected
No	Ref			Ref			Ref
Yes	0.74	(0.52, 1.10)	0.13	0.56	(0.36, 0.86)	0.01	0.95	(0.56, 1.60)	0.85
Receipt of on-site substance abuse counseling
No	Ref			Ref			Ref			Ref
Yes	0.55	(0.37, 0.78)	<0.01	0.54	(0.36, 0.79)	<0.01	0.39	(0.22, 0.67)	<0.01	0.34	(0.19, 0.59)	<0.01
AIC Goodness of Fit					1169.28						502.9

^#Estimates from a Cox Proportional Hazard model

^*Non-significant variables were excluded based on AIC in the multivariate model

AIC = Akaike Information Criterion; Ref = referent