Relation between opioid-related harms and socioeconomic inequalities in Ontario: a population-based descriptive study

Zoe F Cairncross; Jeremy Herring; Trevor van Ingen; Brendan T Smith; Pamela Leece; Brian Schwartz; Karin Hohenadel

doi:10.9778/cmajo.20180084

Relation between opioid-related harms and socioeconomic inequalities in Ontario: a population-based descriptive study

CMAJ Open. 2018 Oct 18;6(4):E478-E485. doi: 10.9778/cmajo.20180084. Print 2018 Oct-Dec.

Authors

Zoe F Cairncross¹, Jeremy Herring², Trevor van Ingen², Brendan T Smith², Pamela Leece², Brian Schwartz², Karin Hohenadel²

Affiliations

¹ Dalla Lana School of Public Health (Cairncross, Smith, Leece, Schwartz), University of Toronto; Public Health Ontario (Cairncross, Herring, van Ingen, Smith, Leece, Schwartz, Hohenadel), Toronto, Ont. zoe.cairncross@mail.utoronto.ca.
² Dalla Lana School of Public Health (Cairncross, Smith, Leece, Schwartz), University of Toronto; Public Health Ontario (Cairncross, Herring, van Ingen, Smith, Leece, Schwartz, Hohenadel), Toronto, Ont.

Abstract

Background: Negative health outcomes associated with the use of both prescribed and nonprescribed opioids are increasingly prevalent. We examined long-term trends in opioid-related harms in Ontario across a set of 6 indicators and the relation between harms and neighbourhood income in 2016.

Methods: We examined rates of neonatal abstinence syndrome, opioid poisoning (fatal and nonfatal) and nonpoisoning opioid-related events from 2003 to 2016 in Ontario using population-based health administrative databases. We conducted descriptive analyses for harm indicators across neighbourhood income quintiles in 2016 (2015 for death). We examined social inequalities in opioid-related harms on both relative (prevalence ratio) and absolute (potential rate reduction) scales.

Results: Rates of opioid-related harms increased dramatically between 2003 and 2016. In 2016, neonatal abstinence syndrome and opioid poisoning and nonpoisoning events showed a strong social gradient, with harm rates being lowest in higher-income neighbourhoods and highest in lower-income neighbourhoods. Prevalence ratios for the lowest-income neighbourhoods compared to the highest-income neighbourhoods ranged from 2.36 (95% confidence interval [CI] 2.15-2.58) for emergency department visits for opioid poisoning to 3.70 (95% CI 2.62-5.23) for neonatal abstinence syndrome. Potential rate reductions for opioid-related harms ranged from 34.8% (95% CI 29.1-40.1) to 49.9% (95% CI 36.7-60.5), which suggests that at least one-third of all harmful events could be prevented if all neighbourhoods had the same socioeconomic profile as the highest-income neighbourhoods.

Interpretation: Rates of opioid-related harms increased in Ontario between 2003 and 2016, and people in lower-income neighbourhoods experienced substantially higher rates of opioid-related harms than those in higher-income neighbourhoods. This finding can inform planning for opioid-related public health interventions with consideration of health equity.