Leaving the emergency department before treatment completion among people with and without HIV with a suspected overdose in British Columbia, Canada

Leaving the emergency department (ED) before treatment completion (LBTC) - either without being seen by a physician or against medical advice - is common in substance use-related presentations and associated with adverse outcomes. We assessed determinants and outcomes of LBTC among people with and without HIV (PWH, PWoH) attending an ED with a suspected overdose between 2012-2020 in British Columbia, Canada, using linked administrative data. We identified suspected overdose events presenting to the ED and classified LBTC using diagnosis codes and/or discharge disposition. Using multivariable regression, we assessed (1) whether HIV was associated with LBTC, (2) determinants of LBTC stratified by HIV-status, and (3) whether LBTC was associated with risk of another overdose-related ED attendance, primary care contact, and OAT dispensation within 30 days. Although LBTC was more common among PWH attending the ED with a suspected overdose (13.9% of 632 presentations) than among PWoH (9.0% of 3,057 presentations), HIV was not independently associated with higher LBTC risk. Determinants of LBTC among PWH were age 19-38, lower triage acuity, ED attendance from 04/2016-03/2020, and opioid agonist therapy in the prior five years. Of note, LBTC was independently associated with increased risk for another overdose-related ED attendance within 30 days (adjusted risk ratio: 1.46; 95%CI: 1.06, 2.01).