Impact of inpatient addiction psychiatry consultation on opioid use disorder outcomes.

Background And Objectives: Addiction consultation services provide access to specialty addiction care during general hospital admission. This study assessed opioid use disorder (OUD) outcomes associated with addiction consultation.

Methods: Retrospective cohort study of individuals with OUD admitted to an academic medical center between 2018 and 2023. The exposure was addiction consultation. Outcomes included initiating medication for OUD (MOUD), hospital length of stay, before-medically-advised (BMA) discharge, and 30- and 90-day postdischarge acute care utilization.

Results: Of 26,766 admissions (10,501 patients) with OUD, 2826 addiction consultations were completed. Consultation cohort was more likely to be young, male, and White than controls. Consultation was associated with greater MOUD initiation (adjusted odds ratio [aOR], 5.07; 95% confidence interval [CI], 4.41-5.82), fewer emergency department visits at 30 (aOR, 0.78; 95% CI, 0.67-0.92) and 90 (aOR, 0.79; 95% CI, 0.69-0.89) days, and fewer hospitalizations at 30 (aOR, 0.65; 95% CI, 0.56 to 0.76) and 90 (aOR, 0.67; 95% CI, 0.59-0.76) days. Additionally, consultation patients were more likely to have a longer hospital stay and leave BMA.

Conclusions And Scientific Significance: Addiction consultation was associated with increased MOUD initiation and reduced postdischarge acute care utilization. This is the largest study to date showing a significant association between addiction psychiatry consultation and improved OUD outcomes when compared to controls. The observed reduction in postdischarge acute care utilization remains even after adjusting for MOUD initiation. Disparities in access to addiction consultation warrant further study.