Matthew Hickman, Annick Borquez and Louisa Degenhardt on using linked government data to demonstrate that opioid agonist treatments for opioid dependence – such as methadone and buprenorphine – prevented drug-related deaths in New South Wales .
…over half of overdose deaths and one-quarter of other cause deaths among the cohort were averted through existing programmes.
Recent global systematic reviews have shown that people who inject drugs are more than 10 times likely to die compared with the general population, and that opioid agonist treatment can reduce this risk by over half (especially by reducing rates of overdose and suicide). Evidence from modelling studies suggests that drug-related deaths could be reduced if more people access treatment, if people in treatment, stay there for a longer time period and if opioid agonist treatment is provided in prisons. Global reviews have also shown that opioid agonist treatment coverage is low in many countries but also that drug-related deaths have continued to rise even in countries with good access to opioid agonist treatment.
Do opioid agonist treatment programmes prevent drug-related deaths?
For the first time, in a new study in Sydney and the Australian State of New South Wales, we evaluated the population-level impact of opioid agonist treatments on drug-related deaths. The model we developed reproduced the treatment and incarceration patterns of nearly 50,000 people who received opioid agonist treatment. We also modeled mortality patterns using cause of death, opioid agonist treatment status and incarceration stage. From 2001 to 2020 there were over 2,000 opioid overdose deaths and over 7,500 deaths in total in the cohort. The model first tested what would have happened if there had been no opioid agonist treatment programmes in either the population or in prison.
For more information, read the research team’s peer-reviewed article:
Modeling the population-level impact of opioid agonist treatment on mortality among people accessing treatment between 2001 and 2020 in New South Wales, Australia. By Antoine Chaillon and colleagues. Published in Addiction (2021).
We found that over half of overdose deaths and one-quarter of other cause deaths among the cohort were averted through existing programmes. In other words, without opioid agonist treatment there would have been an extra 2,250 opioid overdose deaths and nearly 2,000 deaths from other causes. This is equivalent to over 33,000 life-years gained.
The combination of providing a prison opioid agonist treatment programme before linking people to community drug treatment services on release made a big difference and was responsible for 12% of the overall impact of the opioid agonist treatment programme. These two measures in tandem were most effective in averting deaths in the month after release from prison, a time that has been shown to be critical for preventing drug-related deaths.
The high impact of the New South Wales opioid agonist treatment programme over the past 20 years can be attributed to both the high coverage of opioid agonist treatment (more than 50% of people who inject drugs and are opioid dependent are estimated to be in treatment annually) and the good retention and duration of opioid agonist treatment episodes (people are on average in treatment for over 18 months).
Implications for policy and research
Our study shows the huge value of linking drug treatment data and other administrative datasets. This made it possible for us to evaluate the impact of opioid agonist treatment programmes on drug-related deaths. Our study shows the benefits of moving from theoretical models, which suggest that increasing opioid agonist treatment programmes may reduce drug-related deaths, to empirical models, using real-world data, which determine whether this promise is true.
The critical question for opioid agonist treatment programmes in the US, UK and elsewhere in Europe is whether coverage and retention on opioid agonist treatment is good enough to reduce drug-related deaths in the population.
Other countries and regions should now use our model to provide evidence that their opioid agonist treatment programmes save lives. The critical question for opioid agonist treatment programmes in the US, UK and elsewhere in Europe is whether coverage of, and retention in, opioid agonist treatments are good enough to reduce drug-related deaths. And if it is not, what needs to be done so that those programmes do prevent drug-related deaths.
The model in Australia needs to be extended so that it models all drug-related deaths and includes all people who inject drugs who could benefit from opioid agonist treatment. This requires a robust estimate of the prevalence of people who inject drugs, which also can be generated through linking drug treatment and other datasets.
By showing that the opioid agonist treatment programme is having an effect, healthcare workers, policymakers, people with lived experience and others in the community can then focus their energies on other interventions or add-ons to the opioid agonist treatment programme that may be needed to further reduce drug-related deaths and save and improve lives.
by Matthew Hickman, Jack Stone and Peter Vickerman (NIHR Health Protection Research Unit in Behavioural Science and Evaluation, University of Bristol, United Kingdom), Louisa Degenhardt, Chrianna Bharat, Nikki Jones, Sarah Larney, and Michael Farrell (National Drug and Alcohol Research Centre, Sydney, Australia), Annick Bórquez, Antoine Chaillon, and Natasha K. Martin (University of California San Diego, USA)
A version of this article was originally published on the NIHR Health Protection Research Unit in Behavioural Science and Evaluation blog.
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