Prior use of medications for opioid use disorder in ED patients with opioid overdose: prevalence, misuse and overdose severity.

Abstract

Medications for opioid use disorder (MOUD) reduce opioid overdose (OD) deaths; however, prevalence and misuse of MOUD in ED patients presenting with opioid overdose are unclear, as are any impacts of existing MOUD prescriptions on subsequent OD severity. This was a prospective observational cohort of ED patients with opioid OD at two tertiary-care hospitals from 2015 to 19. Patients with confirmed opioid OD (via urine toxicology) were included, while patients with alternate diagnoses, insufficient data, age<18, and prisoners were excluded. OD severity was defined using: (a) hospital LOS (days); and (b) in-hospital mortality. Time trends by calendar year and associations between MOUD and study outcomes were calculated. In 2829 ED patients with acute drug OD, 696 with confirmed opioid OD were included. Overall, 120 patients (17%) were previously prescribed any MOUD, and MOUD prevalence was significantly higher in 2018 and 2019 compared to 2016 (20.1% and 27.8% vs. 8.8%, p<0.05). Odds of MOUD misuse were significantly higher for methadone (OR 3.96 95% CI 2.57-6.12) and lowest for buprenorphine (OR 1.16, p=NS). Mean LOS was over 50% longer for methadone (3.08days) compared to buprenorphine and naltrexone (both 2.0days, p=NS). Following adjustment for confounders, buprenorphine use was associated with significantly shorter LOS (IRR -0.44 (95%CI -0.85, -0.04)). Odds of death were 30% lower for patients on any MOUD (OR 0.70, 95%CI 0.09-5.72), but highest in the methadone group (OR 0.82, 95%CI 0.10-6.74). While MOUD prevalence significantly increased over the study period, MOUD misuse occurred for patients taking methadone, and OD LOS overall was lower in patients with any prior buprenorphine prescription.