Measures of Street Drug Availability and US Drug Overdose Mortality in the Era of Fentanyl and Stimulants

Background Street-sold drugs such as illicitly-manufactured fentanyl and stimulants have replaced prescription opioids as the primary contributors to fatal overdoses in the United States (US), yet the street availability of these substances is challenging to quantify. Building on the foundation of prior research on law enforcement drug seizures, the present study compares a variety of publicly-available drug seizure measures to identify which measures account for the most variation in drug overdose mortality between states, within states over time, and in various US demographic groups. Methods Drug seizure counts from the National Forensic Laboratory Information System and drug overdose mortality rates from the Centers for Disease Control and Prevention were examined for all US states, 2013-2021 (459 state-years). State- and year-fixed effects models regressed drug overdose mortality rates (in the overall population and subpopulations by sex, age, and race/ethnicity) on various drug seizure measures, including rates per population and proportional shares of fentanyl-related, heroin, cocaine, methamphetamine, and xylazine seizures. Results For drug overdose death rates in the overall population and all subpopulations examined by sex, race/ethnicity, and age (except ages 15-29), the model including all drug seizure proportional measures represented the best-performing model examined (as identified via the lowest Akaike Information Criterion and highest within R-squared value), followed by the model including only the fentanyl-related seizure proportion. Conclusions Findingss: upport the utility of publicly-available drug seizure composition measures, especially the proportion of fentanyl-related seizures, as potential proxies for street drug availability across the US and in various subpopulations.