Table 4.

Patient-, physician- and system-level factors associated with delivery of BI/RT by treatment arm

	PCP Arm					NPP & MA Arm
	Coefficient value	Std. err.	OR	95% CI	p value	Coefficient value	Std. err.	OR	95% CI	p value
Patient level
Age
18–24 vs. ≥60	0.2127	0.2119	1.24	(0.82, 1.87)	0.315	0.3589	0.2019	1.43	(0.96, 2.13)	0.075
25–44 vs. ≥60	−0.1290	0.1755	0.88	(0.62, 1.24)	0.462	0.2557	0.1632	1.29	(0.94, 1.78)	0.117
45–59 vs. ≥60	−0.1571	0.1730	0.85	(0.61, 1.20)	0.364	0.5254	0.1615	1.69	(1.23, 2.32)	0.001
Gender
Female vs. Male	−0.5081	0.1166	0.60	(0.48, 0.76)	0.000	−0.4701	0.1067	0.62	(0.51, 0.77)	0.000
Comorbid psychiatric conditions
Yes vs. no	0.1489	0.1403	1.16	(0.88, 1.53)	0.289	0.2391	0.1121	1.27	(1.02, 1.58)	0.033
Chronic diseases
Yes vs. no	−0.0359	0.1165	0.96	(0.77, 1.21)	0.758	0.2444	0.0995	1.28	(1.05, 1.58)	0.014
Physician level
Age
(per 1 year increase)	−0.0608	0.0161	0.94	(0.91, 0.97)	0.000
Gender
Female vs. male	0.2221	0.1932	1.25	(0.86, 1.82)	0.250
Race/ethnicity
Non-white vs. white	−0.5904	0.1599	0.55	(0.41, 0.76)	0.000
Years of services at the health plan
(per 1 year increase)	0.0614	0.0152	1.06	(1.03, 1.10)	0.000
Specialty
Non-internal medicine vs. internal medicine	−0.2045	0.1932	0.82	(0.56, 1.19)	0.290
System level
Colocation of AOD and primary care departments
Yes vs. no	−0.1525	0.5258	0.86	(0.31, 2.41)	0.772	0.6106	0.4493	1.84	(0.76, 4.44)	0.174
MA/PCP ratio at the clinic	−3.1177	0.3265	0.04	(0.02, 0.08)	0.000	−0.4583	0.3325	0.63	(0.33, 1.21)	0.168
Ave. visit time	0.3111	0.0546	1.36	(1.23, 1.52)	0.000	0.0106	0.0529	1.01	(0.91, 1.12)	0.841
Number of PCPs trained at the clinic	−0.1695	0.0360	0.84	(0.79, 0.91)	0.000

A three-level multivariate logistic model adjusting for clustering effects within physician and clinic was run for each of the two intervention arms

BI/RT brief intervention or referral to treatment, PCP primary care physicians, NPP non-physician providers, MA medical assistants, AOD alcohol and other drug