More Americans use illicit opioids such as fentanyl than previously estimated, highlighting the need for better methods to understand the depths of the opioid crisis, according to a new study.
A survey of American adults found that 11% reported illicit opioid use within the past 12 months and 7.5% reported use of illicitly produced fentanyl during the same period, rates that are more than 20 times higher than estimates from a large federal study that annually asks Americans about their use of illicit drugs.
Researchers say the findings add to the evidence that government counts may significantly underestimate illicit drug use and suggest that new methods are necessary to better track a key metric in addressing the nation's opioid crisis. The findings are published in the journal JAMA Health Forum.
"Estimates of illicit opioid use are rare and typically are available only years after the information is collected, limiting our ability to monitor trends on a near-term basis," said David Powell, the study's lead author and a senior economist at RAND, a nonprofit research organization. "Our study offers a method to quickly and repeatedly monitor illicit opioid prevalence at low-cost."
Initially driven by prescription opioids, the opioid crisis in the U.S. transitioned to heroin in the early 2010s and then to illicitly-manufactured fentanyl a few years later.
As the opioid crisis continues to evolve and polysubstance deaths become increasingly common, illegally manufactured fentanyl remains involved in most overdose deaths. Despite the importance of illicit opioids in the current substance-use landscape, relatively little is known about the prevalence of illicit opioid use.
The largest ongoing study that tracks illicit drug use is the National Survey on Drug Use and Health. That study began asking about use of illicitly manufactured fentanyl only in 2022, reporting that 0.3% of adults used the drug that year.
A number of previous studies also have reported higher rates of illicit opioid use, challenging the accuracy of the federal estimate. While researchers say the reasons for the differences are unclear, they suggest it may relate to the way the federal survey asks participants about illicit opioid use.
This includes the fact that about half of the surveys in the federal count are done in person, which may inhibit participants from reporting illicit drug use. Researchers say more work is needed to understand the reason for the differences.
Researchers from RAND and the University of Southern California surveyed 1,515 American adults during June 2024 using a large, representative online panel of Americans. Participants were asked about use of non-prescription opioids within the past 12 months, with heroin and illicitly-manufactured fentanyl given as examples.
A unique aspect of the survey was asking participants about whether they intentionally used illicit opioids, and whether they intentionally or unintentionally used illicitly manufactured fentanyl.
Among those surveyed, 7.7% reported intentional nonprescription opioid use, with another 3.2% reporting unintentional nonprescription opioid use.
Most people who used nonprescription opioids reported illicit fentanyl use. The rate of intentional use of illicitly manufactured fentanyl was 4.9% while the rate of unintentional use of fentanyl was 2.6%.
Among respondents reporting nonprescription opioid use within the past 12 months, 39% reported their first use of opioids involved medication prescribed to them, while 36% reported their first use involved prescription opioids not prescribed to them. The remaining 25% answered that their first exposure to opioids involved illicitly manufactured opioids.
"Ultimately, the data presented here should be treated as a substantive data point for understanding and curtailing the ongoing opioid crisis," said Mireille Jacobson, the study's co-author and an economist at the University of Southern California. "More near real-time information is needed to evaluate not only where we are in the epidemic, but, more importantly, whether we are making progress in reining it in."
One limitation of the survey was the use of an online platform. While similar to national rates in terms of demographics, the surveyed population could be different in unobserved ways. The authors intend to re-examine their findings soon, using a survey platform more robust to these concerns.
Support for the study was provided by Arnold Ventures and the National Institutes of Health's National Institute on Drug Abuse under award numbers R21DA06011 and 2P50DA046351-06A1. The content in this press release is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
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