Proportion of fentanyl reports in illicit drug seizures and nonfatal overdose emergency department visits in the United States, 2021-2024.

BACKGROUND

The increasing presence of fentanyl in the illicit drug supply has been associated with rising overdose mortality in the United States, but the extent to which it is associated with nonfatal overdose morbidity remains unknown. We examined the association between the proportion of fentanyl reports in illicit drug seizures and state-level rates of nonfatal overdose emergency department (ED) visits.

METHODS

We conducted a longitudinal ecological analysis of 40 US states from 2021 to 2024. Outcomes were annual state-level rates of nonfatal overdose ED visits per 10,000 ED visits, obtained from Drug Overdose Surveillance and Epidemiology Syndromic Surveillance System. The proportion of fentanyl reports among all illicit drug seizure reports was obtained from the National Forensic Laboratory Information System. Annual state-level sociodemographic covariates were obtained from the American Community Survey. Adjusted associations and 95% confidence intervals (CIs) were estimated via linear regression using generalized estimating equations.

RESULTS

After adjusting for covariates, a 10 percentage-point increase in fentanyl seizure proportion was significantly associated with higher nonfatal overdose ED visit rates: opioid-involved (2.18 increase, 95% CI: 0.89, 3.46), fentanyl-involved (0.73 increase, 95% CI: 0.27, 1.18), and cocaine-involved (0.08 increase, 95% CI: 0.01, 0.15). There was no evidence of statistically significant associations with heroin-, stimulant-, methamphetamine-, and benzodiazepine-involved overdose ED visit rates.

CONCLUSIONS

Greater fentanyl penetration in illicit drug seizure reports was significantly associated with higher opioid-, fentanyl-, and cocaine-involved nonfatal overdose ED visit rates across states. These findings suggest that fentanyl saturation is not only a driver of overdose mortality but also contributes to nonfatal overdose burden, with important implications for health system demand and public health preparedness.