Association between law enforcement seizures of illicit drugs and drug overdose deaths involving cocaine and methamphetamine, Ohio, 2014-2019

Background: The United States continues to experience a crisis of mounting opioid overdose deaths involving cocaine and methamphetamine (hereafter illicit stimulants). Law enforcement drug seizure data present a unique opportunity to examine the association between illicit-stimulant-involved overdose deaths (ISODs) and the illicit drug supply. Our objective is to better understand correlations between illicit drug market trends and increases in ISODs in Ohio in 2014-2019. Methods: This observational study analyzes the universe of ISODs and drug seizures in Ohio from 2014 to 2019. We use graphs and descriptive statistics to characterize trends over time and estimate a time series model of their association. ISODs were summed to yield monthly statewide counts of seizures containing methamphetamine, cocaine, illicitly manufactured fentanyl (IMF), and other non-IMF opioids (e.g., heroin). All rates were calculated per 100,000 persons. Results: Roughly 80% of ISODs in Ohio from 2014 to 2019 involved an opioid, with IMF co-occurring in 90% of ISODs by 2019. Methamphetamine and cocaine seizures containing IMF were associated with 0.439 (p <.01) and 0.457 (p <.01) additional deaths per 100,000 persons per month, respectively. IMF seizures not containing cocaine nor methamphetamine were also associated with additional ISODs (0.119, p <.01) and seizures of illicit stimulants not containing IMF were not associated with ISODs. Conclusions: The number of ISODs was extremely high when IMF was co-involved and relatively low without IMF involvement. By demonstrating how supply-side trends correspond with ISOD rates, the current study bolsters the analytical utility of law enforcement seizures and complements growing literature in the field.