Table 2.

Unadjusted and adjusted association between Addiction Consult Service (ACS) and 30-day acute care utilization

	Unadjusted OR (95% CI)^*	Adjusted OR (95% CI)^*
Primary Analysis
Full Sample (N=3905 unique subjects, 5979 total observations)	1.16 (0.98, 1.38)	1.02 (0.82, 1.28)

Exploratory Subgroup Analyses
With OUD (N=1378 unique subjects, 2163 observations)	0.98 (0.79, 1.20)	0.87 (0.66, 1.13)
With OUD and medication (N=631 unique subjects, 952 observations)	0.83 (0.61, 1.12)	0.69 (0.47, 1.02)
With OUD without medication (N=850 unique subjects, 1211 observations)	1.16 (0.87, 1.55)	1.06 (0.73, 1.53)

Without OUD (N = 2654 unique subjects, 3816 observations)	1.04 (0.75, 1.44)	1.06 (0.74, 1.52)
Without OUD with medication (N = 249 unique subjects, 353 observations)	1.05 (0.64, 1.73)	1.09 (0.62, 1.90)
Without OUD without medication (N = 2476 unique subjects, 3463 observations)	0.84 (0.53, 1.34)	0.83 (0.50, 1.38)

Legend

All analyses performed reflect represent encounter-level analyses

OUD – Opioid Use Disorder

Medication – continued or started during admission, including the medications methadone, buprenorphine, naltrexone, acamprosate, disulfiram ortopiramate

Adjusted OR - represents an inverse probability of treatment weighting generalized estimating equation logistic model with weights truncated at 99^th percentile, and includes the following variables in the propensity score: age, sex, race/ethnicity, insurance status, housing status, length of stay, ICU stay during admission, psychiatry consult during admission, discharge against medical advice, HIV status, types of substance use disorder^a, number of substance use disorders, naloxone administered, overdose diagnosis, acute complications, COWS ordered, outpatient methadone or buprenorphine, methadone or buprenorphine ordered during admission^a, benzodiazepine or barbiturate ordered during admission

Denotes variables removed from propensity score for secondary analysis of effect modification