Background: Opioid-related deaths in Australia have continued to increase, in part driven by pharmaceutical opioids. Following a period of stabilisation (2001-2012), heroin deaths are again increasing. This paper aims to identify factors driving these trends.

Methods: Deaths attributed by the coroner to heroin (including other drug) toxicity (2001-2022) extracted from the NCIS, an online coronial database containing deaths in Australia and New Zealand. Joinpoint regression analysis for changepoints in trends. Age, period, and cohort analysis using the online US National Cancer Institute tool.

Results: 7,233 heroin-related deaths were identified in Australia (2001-2022); the majority (80%) among males. Deaths increased significantly (1.2 per 100,000 population, 2001-2.5 per 100,000, 2019), with a 4.04% annual percentage change (APC). One significant changepoint occurred in 2020; deaths decreased (APC -28.52%). Deaths among males increased significantly (APC 3.3%); deaths among females increased at a higher rate (APC 4.94%). Age-period-cohort analysis showed Australians aged 51 and older recorded the highest increase in heroin deaths. Period analysis showed higher mortality risk during 2011-2020, compared to 2001, partly driven by increases in co-methamphetamine toxicity (10%- 2011, 37%-2020). Cohort analysis showed relative mortality risk was highest among Generation X (born 1965-1979).

Conclusions: Increasing engagement of older Australians using heroin is crucial, particularly given concurrent methamphetamine use and underlying disease. Greater engagement of women in health/harm reduction services is also warranted. The COVID-19 pandemic has influenced trends, with disruptions in Australian heroin markets recorded early in the pandemic. This contrasts with North America, where opioid-related deaths have increased since the pandemic.