The heart of the opioid epidemic that killed 665,341 people in the United States between 2005 and 2020 shifted geographically from the Pacific Northwest to the East, according to a new geographical analysis.
In a study published in the journal The Lancet Regional Health, epidemiologists at the University of Cincinnati tracked the epicenter of this life-shattering epidemic over space and time across the country, driven largely by a move from prescription opiates to heroin to synthetic substances like fentanyl.
Researchers say this geographic shift can be narrowed between 2013 and 2016 as lawmakers implemented stricter regulations limiting access to opioids and law enforcement began prosecuting doctors for allegedly prescribing them irresponsibly.
In the absence of a legal remedy, many people with substance use disorder began turning to illicit drugs such as heroin and fentanyl, UC College of Arts and Sciences Professor Diego Cuadros said.
"The key message is this is an evolving epidemic," Cuadros said.
Likewise, researchers in UC's Digital Epidemiology Lab discovered that the populations affected by substance use disorder also changed over the course of the deadly epidemic from homogeneously white populations to populations that now include many Black victims. Meanwhile, the substance of choice has shifted from prescription opioids to heroin and now synthetic opioids, the study found.
"Between 2013 and 2016, Black communities started having access to these synthetic opiates. And those communities have been more affected, particularly by fentanyl," Cuadros said.
Researchers identified hot spots in fatal drug overdoses that allowed them to track the spread of the opioid epidemic across the United States between 2005 and 2020. Graphic/UC Digital Epidemiology Lab
Drug overdoses are the leading cause of death for Americans ages 18 to 44, according to the Centers for Disease Control and Prevention, which provided mortality stats for the study.
"Our results suggest that vulnerable populations for substance use disorder mortality were not stable over time," study lead author and UC graduate Santiago Escobar said.
He earned a master's degree in geography at UC and now works as a research assistant at UC's Digital Futures.
"As the supply and demand dynamic of the substance evolved, so, too, did the vulnerable populations," he said. "The type of substances being abused, as well as the means used to access them, were key determinants of which populations suffered a higher mortality."
Study co-author Neil McKinnon, now president of Central Michigan University, noted the benefits of tracking an epidemic over time. He is former dean of UC's Winkle College of Pharmacy.
"The epidemic is really a series of mini-epidemics, which we identify as hotspots, across rural and urban America," he said. "We hope our results will assist those in addressing the opioid crisis."
The research team has been studying the opioid epidemic for much of the past decade. In 2018 they identified hot spots where the opioid epidemic was having a disproportionate effect in Ohio. Subsequently, they identified similar trends nationwide in 2021 using county data to find 25 clusters where the rates of fatal drug overdoses were highest.
And then Cuadros and his students turned their attention to the COVID-19 pandemic.
"Epidemics like HIV are stable. We don't see changes in hotspots. But for COVID, we saw different variants like delta and omicron crop up," he said.
Those variants had a disproportionate effect both in cases of infections and deaths across the United States, he said.
"We have a similar situation here with substance use disorder," Cuadros said. "We're facing an epidemic that is very complex and dynamic and evolves over time."
UC College of Nursing students receive training in deploying drugs such as naloxone that can reverse the effects of an opioid overdose. Photo/ Laura Toerner
Escobar said understanding the populations affected by particular substances can help health officials and policymakers come up with more effective interventions. One effective method was the public distribution of reversal medicines such as naloxone, which is credited with saving tens of thousands of lives in the last 15 years.
"As the changes exhibited in mortality can be closely linked to the substances each population is exposed to, we consider the implementation of early warning systems to be critical," he said. These include the National Drug Early Warning System introduced in 2014 that helps monitor, predict and respond to the rise of new and emerging psychoactive substances.
"Surveillance should be placed not only in mortality peaks but also in the reports of new or adulterated substances entering a specific region," Escobar said. "This information should be readily available both to policymakers and to the general public so that institution-level protocols can be activated. This also enables individuals at risk to take preventive actions."
Escobar said another potential intervention is routine testing of illicit substances to determine if they have been adulterated or spiked with life-threatening synthetic opioids and to warn local drug users publicly of any increasing risks they observe. But Escobar acknowledged the legal challenges this would present.
"It is time to rethink if the strategies used to prevent substance use disorder should be based on policing or harm prevention," he said.
Featured image at top: Research led by the University of Cincinnati found that the epicenter of the opioid epidemic shifted east across the continental United States, driven by changing preferences and availability of drugs. Photo/iStock/PowerofForever
