Supply-side predictors of fatal drug overdose in the Washington/Baltimore HIDTA region: 2016–2020

Drug supply measures and drug overdose mortality in the era of fentanyl and stimulants

“…In this study, seized drug report measures were conceptualized as proxies for the composition of illicit drug supplies, consistent with numerous prior studies (e.g., Gladden et al., 2016 ; Jalal and Burke, 2021 ; Sumner et al., 2022 ; Zibbell et al., 2019 , 2023 ; Zoorob, 2019 ). In contrast, several studies (e.g., Lowder et al., 2022 ; Mohler et al., 2021 ; Ray et al., 2023 ) have examined seized drug reports as law enforcement operations with the potential to either reduce overdose deaths (by limiting the availability and use of potentially lethal substances) or increase overdose deaths (by disrupting opioid tolerance levels and shifting individuals who use drugs to less familiar drug sources and products of unknown potency). The present study, however, was not based on the notion that seized drug reports directly impact rates of drug overdose mortality, but rather that higher proportional representation of potent substances (e.g., fentanyl, carfentanil) in seized drug reports is indicative of greater pervasiveness of these substances in street drug supplies, accompanied by more use of (or exposure to) these substances relative to others, and a higher rate of fatal overdoses.…”

“…For example, a state's increase in overall enforcement activities following a policy change may be reflected in higher rates of drug reports, but such increases in overall enforcement activities would not likely impact the percentage of drug reports involving a certain substance. With the exception of a few studies that have included percentage-based measures ( Zibbell et al., 2019 , 2023 ) the majority of studies on associations between seized drug reports and overdose mortality have examined counts or rates ( Gladden et al., 2016 ; Hall et al., 2021 ; Jalal and Burke, 2021 ; Lowder et al., 2022 ; Rosenblum et al., 2020 ; Slavova et al., 2017 ; Sumner et al., 2022 ; Tran et al., 2021 ; Zibbell et al., 2022 ; Zoorob, 2019 ). Findings from the present study, however, support the potential utility of proportion-based drug report measures.…”

“…With respect to stimulants, prior studies report mixed or inconsistent associations between seized stimulant reports and overdose mortality outcomes ( Ray et al., 2023 ; Lowder et al., 2022 ; Zibbell et al., 2022 , 2023 ). The present study's correlation analyses examining between-state variation suggested that states with higher proportions of methamphetamine in seized drug reports were states with lower drug overdose mortality rates, possibly because methamphetamine is most concentrated in the western US (Supplemental Fig.…”

“…Several recent studies have examined associations between seized drug reports and measures of overdose mortality or have developed methods of using seized drug reports to forecast or predict overdose deaths as part of early warning systems. Many of these studies have focused on data from a single state or area (e.g., Hall et al., 2021 ; Mohler et al., 2021 ; Lowder et al., 2022 ; Ray et al., 2023 ; Rosenblum et al., 2020 ; Slavova et al., 2017 ; Tran et al., 2021 ; Zibbell et al., 2019 , 2022 ), while fewer have examined multiple states or the entire US ( Jalal and Burke, 2021 ; Gladden et al., 2016 ; Marks et al., 2021 ; Sumner et al., 2022 ; Zibbell et al., 2023 ; Zoorob et al., 2019 ). These studies have varied in terms of specific drug reports examined (e.g., opioids, stimulants), types of drug overdose mortality outcomes (e.g., drug overdose mortality overall, opioid-involved overdose mortality), and units of analysis (e.g., state-year, county-month).…”

“…Overall, the present study aims to identify the extent to which a variety of measures from the publicly accessible National Forensic Laboratory Information System account for variation in drug overdose mortality between states and within states over time in various subpopulations of the US. The study uses a national, publicly available data source to evaluate measures that are accessible to all researchers/agencies and available for all states in the US, as many prior studies (e.g., Lowder et al., 2022 ; Ray et al., 2023 ; Tran et al., 2021 ; Zibbell et al., 2019 ) have utilized state-specific data sources that are not nationally publicly available but include more detailed, in-depth measures (e.g., weekly or monthly data, weights or doses of drugs seized). Findings from the present study may serve as a reference for researchers seeking optimal nationally available measures of the illicit drug supply for statistical controls in evaluations of policy or socioeconomic influences on drug overdose, or for public health agencies considering measures to include in early warning systems (e.g., Hall et al., 2021 ; Marks et al., 2021 ; Sumner et al., 2022 ) for overdose mortality trends.…”