Descriptive Analysis of Inpatient and Outpatient Cohorts Seeking Treatment After Prescription Opioid Misuse and Medical Toxicology Evaluation.

Introduction: Medical toxicology expertise has expanded into the addiction medicine realm including outpatient medication for opioid use disorder (MOUD) and addiction treatment. Concomitantly, the emergency department (ED) and hospital are increasingly seen as important sites for the screening, prevention, and treatment of patients with substance use disorders and addiction. This analysis seeks to characterize patients seen by medical toxicologists for opioid use and opioid use disorder (OUD) in the ED and inpatient consultation setting (inpatient) versus in the OUD clinic (outpatient) setting.

Methods: We searched the American College of Medical Toxicology's Toxicology Investigators Consortium Case Registry, a prospective, de-identified, national dataset that includes patients receiving medical toxicology consultation following prescription opioid misuse. The dataset also includes patients seen in outpatient MOUD clinics during the same period between June 2013 and November 2015. Intentional self-harm patients were excluded. We analyzed medical history, drug use patterns, and other factors with odds ratios and confidence intervals.

Results: Of 110 patients identified, 60 (54.5%) were inpatients and 50 (45.5%) outpatients. Mean age (39 years), gender (68% male), and race breakdown (60% white/non-Hispanic) were similar. The outpatient group was more likely to have Medicare/Medicaid coverage (p<0.0001). By history, the outpatient group was more likely to have past alcohol misuse, intravenous drug use, prescription drug misuse, and prescription opioid misuse. Most inpatient group members sought a recreational high compared to avoiding withdrawal or treating dependence in the outpatient group.

Conclusion: Patients treated in the outpatient compared to inpatient setting were more likely to report adverse sequelae from their drug use including long-term drug use, depression, previous rehabilitation attempts, and seeking to avoid withdrawal.