Association of Emergency Department Buprenorphine Initiation With Subsequent Pharmacotherapy and Outcomes Among...

To examine trends in emergency department (ED) buprenorphine initiation and evaluate its association with outcomes in the 180 days following discharge.

This observational cohort study used 2018-2022 New Jersey Medicaid claims data from patients presenting to EDs for opioid-related causes, excluding visits that resulted in inpatient admission. We used prescription and encounter data to identify patients with opioid use disorder (OUD) or opioid overdose who initiated buprenorphine in the ED and propensity score matching to compare outcomes of initiators and noninitiators. Outcomes measured during 180-day follow-up were the proportion of days covered (PDC) with medication for OUD (MOUD) and the number of drug overdoses, opioid overdoses, and all-cause ED/inpatient visits within 180 days.

Buprenorphine was initiated in 978 of 24,732 (4.0%) opioid-related ED visits, with this proportion increasing from 0.8% in 2018 to 7.1% in 2022. Buprenorphine initiation was associated with greater MOUD PDC (β=0.10, 95% CI: 0.08-0.13) and fewer all-cause ED/inpatient visits (IRR=0.87, 95% CI: 0.77-0.98) during follow-up. We did not find a statistically significant association between ED buprenorphine initiation and postdischarge overdose; however, greater PDC in the 180-day follow-up period was associated with fewer drug overdoses (IRR=0.80, 95% CI: 0.68-0.94), opioid overdoses (IRR=0.78, 95% CI: 0.67-0.91), and all-cause ED/inpatient visits (IRR=0.89, 95% CI: 0.82-0.96).

EDs play a central role in initiating patients on MOUD, but longer-term outcomes likely depend on multiple factors that may go beyond the scope of ED practice. Further efforts are needed to support MOUD retention and reduce the risk of adverse outcomes following opioid-related ED visits.