Comparing the contribution of prescribed opioids to opioid-related hospitalizations across Canada: A multi-jurisdictional cross-sectional study

Background: The Canadian opioid crisis is a complex, multifaceted problem involving prescribed, diverted and illicitly manufactured opioids. This study sought to characterize the contribution of prescribed opioids to opioid-related hospitalizations in Canada. Methods: We conducted a cross-sectional study of all individuals who were admitted to hospital for opioid toxicity in British Columbia (BC), Manitoba and Ontario between April 2015 and March 2016. We used prescription claims to ascertain active prescription opioid use at time of hospital admission. In secondary analyses, we defined recent opioid prescriptions as those that were dispensed in the 30 and 180 days up to and including admission, and the prevalence of active co-prescription of benzodiazepines with opioids at time of overdose. Results: We identified 2599 instances of opioid toxicity over the study period. In BC, 34.1% of hospital visits for overdose occurred in people with an active opioid prescription, compared to 52.2% (47 of 90) in Manitoba and 52.8% (804 of 1524) in Ontario. However, active opioid prescriptions prior to overdose varied significantly by age and sex. Co-prescription of opioids and benzodiazepines prior to overdose ranged from 17.1% in BC to 35.6% in Manitoba. Conclusions: There remains an important ongoing contribution of prescribed opioids to overdoses across Canada, but non-prescribed opioids play a growing role, particularly in BC. These findings underscore the importance of more judicious opioid prescribing, harm reduction programs, and improved access to addiction care for people with an opioid use disorder.