The association between opioid prescribing and opioid-related mortality within neighborhoods in Ontario, Canada: a case control study

Objective — Recent Canadian data shows that the prescribing of opioids has declined while the number of opioid deaths continue to rise. This study aimed to assess the relationship between neighbourhood-level opioid prescription rates and opioid-related mortality amongst individuals without an opioid prescription.

Methods — This was a nested case-control study using data in Ontario from 2013-2019. Neighbourhood level data was analyzed by using dissemination areas which consists of 400 to 700 people. Cases were defined as individuals who had an opioid-related death without an opioid prescription filled in the year prior. Cases and controls were matched using a disease risk score. After matching, there were 2,401 cases and 8,813 controls. The primary exposure was the total volume of opioids dispensed within the individual’s dissemination area in the 90 days prior to the index date. Conditional logistic regression was used to examine the association between opioid prescriptions with and the risk of overdose.

Results — There was no significant association between the total volume of opioid prescriptions dispensed in a dissemination area and opioid-related mortality. In sub-group analyses stratifying the cohort into prescription and non-prescription opioid related mortality, the amount of prescriptions dispensed was positively associated with prescription opioid related mortality. There was also a significant inverse association between increased total volume of opioids dispensed and non-prescription opioid mortality.

Conclusion — Our results suggest that prescription opioids dispensed within a neighborhood can have both potential benefits and harms. The opioid epidemic requires a nuanced approach that ensures appropriate pain care for patients while also creating a safer environment for opioid use through harm reduction strategies.