Temporal trends in emergency department opioid prescribing and related harms in Alberta, Canada: A population-based...

Emergency department (ED) opioid prescribing has been implicated in the opioid crisis, yet Canadian ED prescribing patterns and related harms remain poorly described. We analyzed trends in ED opioid prescribing and adverse outcomes in Alberta, Canada, from 2010 to -2020.

We conducted a population-based retrospective cohort study using linked administrative health data for all Alberta ED visits, 2010-2020. We included discharged patients ≥ 12 years and excluded those with long-term opioid use (LTU) or possible opioid use disorder (OUD; prior opioid-related ED visit, hospitalization, or opioid agonist therapy). We measured opioid dispensations within three 3 days of discharge and adverse events (LTU and possible OUD) within 12 months. Interrupted time series assessed associations between opioid prescribing guidelines (United States (US): March 2016; Canada: May 2017), prescribing rates, and adverse events.

Among 12.1 million ED visits, opioids were prescribed in 7.4% overall, rising from 6.8% (2010) to 8.2% (2016), then declining to 7.1% (2020). Of those prescribed opioids, 3.6% developed LTU and 0.12% possible OUD within one 1 year. LTU incidence decreased over time and appeared uncorrelated with prescribing rates, while possible OUD increased steadily. The US guideline release was associated with reduced prescribing; Canadian guidelines had no impact.

ED opioid prescribing in Alberta peaked in 2016 before declining. Prescribing rates did not correlate with adverse outcomes (LTU or possible OUD). This decoupling of exposure from outcomes suggests a limited role for ED prescribing in the opioid crisis.