Theme: Epidemiology & Public Health Research Year: 2024
Background: Across Canada, the COVID-19 pandemic occurred amidst an ongoing drug toxicity crisis. People diagnosed with opioid use disorder (OUD), are most frequently impacted by harms related to substance use. However, it is currently unknown if the pandemic resulted in disproportionate increases in opioid toxicities among this population.
Methods: We conducted a population-based time series analysis using interventional autoregressive integrated moving average (ARIMA) models to examine the impact of the pandemic-related state of emergency (March 2020) on monthly rates of opioid toxicities between January 1, 2014, and December 31, 2021. We used administrative healthcare data housed at ICES. We measured opioid toxicities as a monthly count of events reported per 100,000 population. Analyses were stratified by people with and without OUD.
Results: Overall, we identified 80,296 opioid toxicities among 52,052 individuals. Over half (53.5%) of opioid toxicities occurred among people with OUD. We observed a four-fold increase in monthly opioid toxicities between January 2014 (N=356; 2.6 per 100,000 population) and December 2021 (N=1,571; 10.5 per 100,000) which differed among people with OUD (0.8 to 7.4 per 100,000) and without OUD (1.8 to 3.1 per 100,000). We observed a significant ramp increase in the overall rate of opioid toxicities following the declaration of a pandemic emergency [0.2 per 100,000 monthly (~30/month), 95% CI: 0.029, 0.36, p=0.02]. We found a similar ramp increase among people with OUD (0.2 per 100,000 monthly, 95% CI: 0.10, 0.28, p <.001), however this was non-significant among people without OUD (p=0.95).
Conclusion: The rate of opioid toxicities has continued to grow across Ontario, with a substantial prolonged acceleration during COVID-19. The important differences observed among people with OUD compared to those without, highlights the critical need for improved access to harm reduction programs and the continued monitoring of opioid-related harms post-pandemic.