by Heather Sanders
Opioid use and its associated harms have been referred to as North America’s “other epidemic.”
Since the start of the pandemic, this public health concern has become even more critical. Social isolation and disruption to drug supply have resulted in an increase in overdose deaths, the majority of these related to opioid use. According to the B.C. Coroners Service, between January and July of 2021 British Columbia recorded over 1000 overdose deaths, surpassing previous records. Ontario and Alberta also broke records. The National Institute on Drug Abuse reported that in 2020 over 93,000 people in the United States died from overdose – the most in any one-year period in history. And it’s not just overdose that is a concern. Opioid use disorder (OUD) is associated with other serious health risks including outbreaks of HIV, hepatitis C, and blood borne infections.
Yet across North America, policymakers struggle with how to address the crisis. Providing harm reduction services such as safe drug supply, supervised injection sites and alternative therapies are considered controversial and expensive. Housing, healthcare, ongoing counselling and support are costly, inaccessible or ineffective. While many evidence-based interventions for people who use opiates are available, they are significantly underutilized. It is estimated that only one in four Americans with an opioid use disorder has received any care.
Bohdan Nosyk, professor of health sciences at SFU and the St. Paul's Hospital CANFAR Chair in HIV/AIDS Research wants to improve access to harm reduction services for people who use opioids. He leads an ongoing study assessing the quality of care for people with OUD in B.C., in partnership with the Ministry of Mental Health and Addictions, people with lived experience, policy makers, physicians and scholars. He is also part of the Opioid Use Disorder Modelling Group – a consortium of researchers from SFU, Weill-Cornell Medical College, Harvard University, the University of Toronto, the B.C. Centre for Disease Control, and others.
The OUD Group proposes using simulation models to help guide and inform clinical and public health responses. These models combine an understanding of OUD with the best available data, to simulate populations of interest, predict future trajectories and forecast the outcomes of different levels of interventions and health policies across diverse jurisdictions. The group recently published the paper: How simulation modeling can support the public health response to the opioid crisis in North America: Setting priorities and assessing value.
“We want to use evidence-based simulations to promote harm reduction, and bring these findings to policy makers,” says Professor Nosyk. “The reality is that the level of investment and research into studying opioid use disorder falls far short of the investment put into understanding and treating other diseases like HIV and cancer. Both of these diseases had large and successful collaborations with modelling groups, which advanced their science.” He explains that the Group hopes to bring people together to build upon the quality and scope of work to better understand OUD. Their paper sets out priorities for what needs to be done in the field.
Using simulations to predict the outcome of various harm reduction strategies has numerous benefits. For example, clinical trials are often limited by their short time scales, but simulation models can gather long term population and economic impact data. And while funding for interventions may only be available short term, models can help inform which interventions are the most effective in each jurisdiction and offer suggestions for the best use of resources. Simulation models can provide insight not just into health outcomes and economic costs, but can also include effects related to crime, housing, and other social factors. And they can be used to inform emergency response and fast-paced decision making.
Furthermore, models can simulate studies that may be controversial or prohibitively expensive to conduct, while extrapolating study data to include populations not included in clinical trials. They also help explore how evidence generated in one geographic or policy context can be applied to different contexts. “If you propose a question, we can build a simulation to answer that question,” says Nosyk.
The authors of the paper point to several fascinating findings of simulation modelling. For example, a recent study was able to model the number of supervised injection sites needed for two Canadian cities, suggesting three in Toronto and two in Ottawa would meet required service levels while remaining cost-effective.
Recent simulation analyses have investigated the different pathways of opioid use initiation, including the observed transition from prescription opioid to heroin use, as well as the transition from heroin to fentanyl – data that can inform the impact of interventions. Another recent modeling application noted the effect on HIV transmissions as susceptible and infected populations experienced increasing rates of fatal ODs.
In the U.S., a modeling study found that policies reducing the opioid prescription supply successfully reduced deaths but also led some individuals to switch to heroin use, which increased heroin-related deaths. Perhaps over the long term some policies may avert enough new cases of OUD to outweigh the harms, however analysis has predicted that reducing the supply of prescription opioids without expanding access to treatment is unlikely to end the current crisis.
Nosyk acknowledges that B.C. has one of the most comprehensive population-level health databases in Canada which includes health and social services data across a person’s lifetime. What’s not captured however is the use of harm reduction services such as naloxone distribution and supervised injection site attendance, which challenges the efforts to quantify potential unmet needs across the province. “We do have much to learn from other jurisdictions,” he says. For example, Massachusetts’ Public Health Data Warehouse links ten statewide databases – the most comprehensive resource on opioid addiction treatment in the U.S.
The OUD group would like to see more collaboration across this specific study area to gather the data needed to answer the most pressing questions. These include context-specific interventions, how to combine intervention strategies for the best outcomes, and how to ensure limited resources are used sustainably and efficiently.
Most importantly, according to Nosyk is building the hard evidence needed by policymakers to implement the programs that will improve health and save lives. The opioid crisis is a disease characterized by “despair, poverty and marginalization,” he says. “The pandemic has only made it harder to reach people who need harm reduction services.”
Nosyk argues that regardless of the illness, the investment in a person’s well-being needs to fall in line with other disease areas and that’s what the OUD group is trying to achieve. “When we talk about the effectiveness of different treatments and services, we’re not looking at the specific disease. A year of life in good health has the same value whether we are treating arthritis or heart disease or addiction. We need hard evidence to make the case for the interventions needed by this marginalized population. To me it’s about equity, and it’s about treating people who use drugs as human beings, worthy of compassionate care.”