The impact of addiction medicine consultation on outcomes in hospitalized patients

Abstract Background Over the last several years, the incidence and prevalence of substance use disorders (SUD) and related acute illnesses have been rising in the US. Their diagnosis of SUD impacts the clinical course of many hospitalized patients. The primary objective of our study is to assess the impact of a newly implemented inpatient addiction medicine consult service on outcomes in patients with a SUD. Methods We included adult SUD patients hospitalized for 24 hours or greater between March 2018 and January 2022. We recorded demographic and clinical variables and analyzed the association between the occurrence of addiction medicine consultation (AMC) with the outcomes of left against medical advice (AMA) and 30-day readmission (READ). Results There were 1,020 encounters included in our study: 945 (93%) without AMC and 75 (7%) AMC. AMC patients were younger (53.2 vs. 56.93, P < 0.001), were often male (22.7% vs. 13%, P < 0.001), or had health insurance (74.7% vs. 85.4%, p = 0.015). Their years of use (30 years) and hospital length of stay (4 days) were similar between AMC and non-AMC groups. More patients were using intravenous drugs in the AMC group (25.3% vs 9.8%, < p < 0.001) and opioids (50.7% vs. 19.3%, P < 0.001). In a multivariate regression analysis for the outcomes of interest, after adjusting for demographic variables, AMC was not associated with the outcome AMA (P = 183) but was shown to have a much lower likelihood of 30-day readmission (0.3[0.1–0.8], P = 0.016). Conclusion We found that the practice of AMC was associated with similar rates of AMA but fewer 30-day readmission rates in patients with SUD. The comparable rate of AMA could be due to clinicians' higher propensity to consult AMC if patients threaten to leave the hospital. The findings of our study should be confirmed in larger trials but hold significant promise.