U.S. rates of heroin use, heroin use disorder, and heroin injections all increased overall among adults during a recent 17-year period, but rates have plateaued, new research shows.
Although on the face of it this may seem like good news, investigators at the Substance Abuse and Mental Health Services Administration (SAMHSA) note that the plateau in heroin use may simply reflect a switch to fentanyl.
“The recent leveling off of heroin use might reflect shifts from heroin to illicit fentanyl-related compounds,” wrote the investigators, led by Beth Han, MD, PhD, MPH.
The study was published online Feb. 11 as a research letter in JAMA (2020;323[6]:568-71).
National data
For the study, researchers collected data from a nationally representative group of adults aged 18 years or older who participated in the 2002-2018 National Survey on Drug Use and Health (NSDUH).
The analysis included 800,500 respondents during the study period. The mean age of respondents was 34.5 years, and 53.2% were women.
Results showed that the reported past-year prevalence of heroin use increased from 0.17% in 2002 to 0.32% in 2018 (average annual percentage change [AAPC], 5.6; 95% confidence interval [CI], 1.0-10.5; P = .02). During 2002-2016, the APC was 7.6 (95% CI, 6.3-9.0; P less than .001) but then plateaued during 2016-2018 (APC, –7.1; 95% CI, –36.9 to 36.7; P = .69).
The prevalence of heroin use disorder increased from 0.10% in 2002 to 0.21% in 2018 (AAPC, 6.0; 95% CI, 3.2-8.8; P less than .001). The rate remained stable during 2002-2008, increased during 2008-2015, then plateaued during 2015-2018.
The prevalence of heroin injections increased from 0.09% in 2002 to 0.17% in 2018 (AAPC, 6.9; 95% CI, 5.7-8.0; P less than .001), although there was a dip from the previous year. This rate increased during the study period among both men and women, those aged 35-49 years, non-Hispanic whites, and those residing in the Northeast or West regions.
For individuals up to age 25 years and those living in the Midwest, the heroin injection rate stopped increasing and plateaued, but there was an overall increase during the study period.
In 2018, the rate of past-year heroin injection was highest in those in the Northeast, those up to age 49 years, men, and non-Hispanic whites.
More infectious disease testing
Prevalence of heroin injection did not increase among adults who used heroin or who had heroin use disorder. This, the researchers note, “suggests that increases in heroin injection are related to overall increases in heroin use rather than increases in the propensity to inject.”
Future research should examine differences in heroin injection trends across subgroups, the authors wrote.
The researchers advocate for expanding HIV and hepatitis testing and treatment, the provision of sterile syringes, and use of Food and Drug Administration–approved medications for opioid use disorders, particularly among populations at greatest risk – adults in the Northeast, those aged 18-49 years, men, and non-Hispanic whites.
“In parallel, interventions to prevent opioid misuse and opioid use disorder are needed to avert further increases in injection drug use,” they noted.
A limitation of the study was that the NSDUH excludes jail and prison populations and homeless people not in living shelters. In addition, the NSDUH is subject to recall bias.
The study was jointly sponsored by SAMHSA and the National Institute on Drug Abuse of the National Institutes of Health. One author reports owning stock in General Electric Co, 3M Co, and Pfizer Inc.
A version of this article first appeared on Medscape.com.