(C-092) Trends in opioid prescribing prior to opioid toxicity inpatient hospitalizations and ED visits in Canada, 2018-2022

Background: Despite evidence of changing role of pharmaceutical opioids in opioid-related harms in Canada, little is known about patterns of opioid prescribing prior to opioid-related toxicity harms and how it varies provincially.

Objectives: To describe patterns of prescription opioid exposure at the time of opioid toxicity inpatient hospitalizations and ED visits.

Methods: We conducted a population-based repeated cross-sectional study of opioid toxicity (i) acute inpatient hospitalizations and (ii) ED visits in 5 and 6 Canadian provinces, respectively between January 1st, 2018 and December 31st, 2022. We linked pharmacy dispensing data across included provinces―British Columbia (BC), Alberta (AB), Saskatchewan (SK), Manitoba (MB), Ontario (ON) and Quebec (QB)―to determine active prescription opioid dispensations at the time of opioid toxicity, overall and stratified by patient characteristics and type of opioid dispensed. In our secondary analyses, we examined recent prescription opioid dispensations in the prior (i) 30 days and (ii) 180 days.

Results: Active prescription opioid exposure at the time of opioid toxicity hospital admission was relatively uncommon and declined across provinces over the study period, apart from BC (range, 20.0% in BC to 47.5% in QB in 2018; 19.7% in BC to 36.5% in QB in 2022). Active opioid exposure was even less common at the time of opioid toxicity ED visit and similarly declined over time in most provinces (range, 11.0% in BC to 28.5% in QB in 2018; 14.9% in AB to 26.0% in QB in 2022). Generally, people older than 65 and females were proportionally more likely to have an active opioid exposure. We observed a shift towards active exposure to OAT across provinces, while active exposure to opioids for pain declined over time.

Conclusions: On average, pharmaceutical opioid exposure at the time of opioid-related toxicity has declined over time when measured in relation to overall opioid toxicity events. Our findings highlight increasing harms of the unpredictable, potent unregulated drug supply across the country as well as important differences in prescription opioid exposure across demographics.