Impact of the COVID-19 pandemic on opioid toxicity mortality rates in Nova Scotia: An interrupted time series analysis (2009-2023).

OBJECTIVES

To examine trends in opioid toxicity mortality in Nova Scotia and its health zones from 2009 to 2023, focusing on differences between pharmaceutical and non-pharmaceutical opioid-related deaths.

METHODS

We conducted a population-based study using data on annual opioid toxicity mortality rates from 2009 to 2023, stratified by health zone and opioid type. An interrupted time series (ITS) analysis was applied to assess changes in mortality trends across three pandemic-related periods. Comparisons were made between pharmaceutical and non-pharmaceutical opioid mortality to assess evolving patterns of opioid-related harm.

RESULTS

Opioid toxicity mortality in Nova Scotia declined during the peri-pandemic period (2019-2021) but increased significantly post-pandemic, particularly in non-pharmaceutical opioid-related deaths, which steadily rose after 2021. Pharmaceutical opioid-related deaths remained higher than non-pharmaceutical deaths. Health zone analysis revealed geographic variation: the Central Zone experienced stable pharmaceutical mortality with rising non-pharmaceutical deaths post-pandemic; the Eastern Zone saw higher pharmaceutical mortality pre-pandemic, which declined during the peri-pandemic period, while non-pharmaceutical deaths remained low; the Northern Zone had stable pharmaceutical mortality but rising non-pharmaceutical deaths post-pandemic; and the Western Zone exhibited consistently lower mortality rates across both opioid types.

CONCLUSION

This study reveals significant shifts in opioid-related mortality trends in Nova Scotia, with a rise in non-pharmaceutical opioid deaths post-pandemic, while pharmaceutical opioids remain a major contributor. Geographic variations across health zones highlight the need for region-specific public health strategies. Ongoing efforts to reduce both pharmaceutical and illicit opioid misuse through harm reduction and improved prescribing practices are crucial.