Table 2:

Initiation Models

Model Number	1	2	4	5
	Race	1 + Controls	2 + Mediators	4 + Interactions

	Coefficient	Coefficient	Coefficient	Coefficient
	(95% CI)	(95% CI)	(95% CI)	(95% CI)
Black race (vs. White)	−0.209^**	−0.182^**	−0.139^**	−0.145^**
Black race (vs. White)	(−0.242 - −0.177)	(−0.215 - −0.148)	(−0.172 - −0.106)	(−0.194 - −0.095)

Controls:
Ages 30-39 (vs. 18-29)		0.033^*	0.02	0.02
Ages 30-39 (vs. 18-29)		(0.003 - 0.064)	(−0.010 - 0.050)	(−0.010 - 0.050)
Ages 40-49 (vs. 18-29)		0.047^*	0.031	0.031
Ages 40-49 (vs. 18-29)		(0.010 - 0.084)	(−0.005 - 0.067)	(−0.005 - 0.068)
Ages 50-64 (vs. 18-29)		0.053^**	0.016	0.016
Ages 50-64 (vs. 18-29)		(0.014 - 0.092)	(−0.023 - 0.054)	(−0.022 - 0.055)
Male (vs. Female)		−0.035^**	−0.01	−0.01
Male (vs. Female)		(−0.060 - −0.010)	(−0.035 - 0.015)	(−0.035 - 0.015)
SSI Medicaid eligibility		−0.149^**	−0.148^**	−0.147^**
SSI Medicaid eligibility		(−0.182 - −0.116)	(−0.180 - −0.116)	(−0.179 - −0.115)
Expansion Medicaid eligibility		0.021	0.017	0.017
Expansion Medicaid eligibility		(−0.008 - 0.050)	(−0.011 - 0.046)	(−0.012 - 0.046)

Possible Mediators: ^†
Non-OUD SUD Diagnosis			−0.049^**	−0.039^*
Non-OUD SUD Diagnosis			(−0.077 - −0.021)	(−0.070 - −0.007)
Days in Allegheny County Jail			−0.003^**	−0.003^**
Days in Allegheny County Jail			(−0.003 - −0.002)	(−0.003 - −0.002)
Months with Housing Support			−0.009	−0.006
Months with Housing Support			(−0.017 - 0.000)	(−0.017 - 0.005)
Days in ED			−0.010^**	−0.012^**
Days in ED			(−0.015 - −0.006)	(−0.018 - −0.007)
Intensive SUD treatment utilization (non-MOUD)			−0.080^**	−0.082^**
Intensive SUD treatment utilization (non-MOUD)			(−0.106 - −0.054)	(−0.110 - −0.054)

Black race (vs. White) Interacted with… ^§
Non-OUD SUD Diagnosis				−0.048
Non-OUD SUD Diagnosis				(−0.116 - 0.021)
Days in Allegheny County Jail				0.001
Days in Allegheny County Jail				(−0.000 - 0.002)
Months with Housing Support				−0.005
Months with Housing Support				(−0.023 - 0.013)
Days in ED				0.006
Days in ED				(−0.003 - 0.015)
Intensive SUD treatment utilization (non-MOUD)				0.016
Intensive SUD treatment utilization (non-MOUD)				(−0.051 - 0.083)
Constant	0.506^**	0.524^**	0.602^**	0.603^**
Constant	(0.493 - 0.520)	(0.495 - 0.552)	(0.571 - 0.632)	(0.572 - 0.635)

Observations	6,374	6,374	6,374	6,374
R-squared	0.025	0.043	0.085	0.086
R-squared Adj.	0.025	0.043	0.085	0.086

^**

p<0.01,

p<0.05

^†

Mediators with which race had a significant relationship in models 3a (appendix) and a significant association with initiation in models 3b (appendix) were included in model 4, in which we regressed initiation on all relevant mediators and control variables.

^§

Interaction terms between possible mediators and race to identify any moderation effect by race.