Which patients receive an addiction consult? A preliminary analysis of the INREACH (INpatient REadmission post-Addiction Consult Help) study

Introduction: Despite the high prevalence and significant health risks of substance use disorders (SUDs), a minority of individuals with SUDs receive treatment of any kind. The aims of this study are to describe inpatients with an SUD who receive an addiction consult at a large urban safety net hospital and explore characteristics associated with receiving an addiction consult. Methods: This is a retrospective cohort study of all adult patients with a discharge diagnosis of an SUD from July 2015 to July 2016. A generalized estimating equation (GEE) logistic regression model was used to explore patient factors associated with receipt of an addiction consult, such as demographics, social, medical, and SUD characteristics. Results: A total of 3905 patients with SUD diagnoses with 5979 hospitalization encounters were included in this study. There were 694 addiction consults (11.6%, 95% CI: 10.71% to 12.5%) across all of the encounters and 576 unique patients that received consults. Patients with opioid use disorder had higher odds of receiving a consult (Adjusted Odds Ratio: 6.39, 95% CI 5.14-7.94), as did patients with acute complications from their substance use (AOR: 1.64, 95% CI 1.34-2.02), patients with human immunodeficiency virus (HIV) (AOR: 2.06, 95% CI 1.59-2.67), and homeless patients (AOR: 1.31, 95% CI 1.08-1.59). Patients with a psychiatry consult had higher odds of receiving an addiction consult (AOR: 1.75, 95% CI 1.37-2.23), and so did patients receiving benzodiazepines and/or phenobarbital (AOR: 1.88, 95% CI 1.55-2.28). Older patients (AOR: 0.82, 95% CI 0.76-0.88 per 10 year increase) had lower odds of receiving a consult, as did patients with an overdose diagnosis (AOR: 0.71, 95% CI 0.53-0.96). Conclusion: A minority of inpatients with SUD received an addiction consult, however, inpatients with opioid use disorder, acute complications (medical, mental health) and homelessness had higher odds of receiving an addiction consult. Patients surviving overdose, a severe acute complication of substance use, had lower odds of receiving a consult and, thus, warrant development of care pathways to provide overdose prevention and addiction treatment engagement.