Patterns of Drugs Involved in Fatal Overdose and Demographic Correlates: A Latent Class Analysis of Polysubstance-Involved Deaths in the Urban Midwest.

Background: Fentanyl contributes to the majority of overdose deaths in the United States but the risk of fatal overdose increases when other substances are involved. Although polysubstance overdose involving fentanyl and stimulants has been characterized as increasing nationally and in urban coastal cities, little is known about patterns of drugs involved in fatal overdose in the urban Midwest.

Methods: The current study examined drug-involved death data from St. Louis City and County. Cases included were drug overdose deaths occurring from 2016 to 2021 (N = 4088; 73% male; 50% white, 49% black). Latent class analysis was used to examine prototypical patterns and demographic associations.

Results: Results indicated fentanyl was involved in the majority (75.0%) of overdose deaths. A five-class solution best fit the data, characterized by deaths involving: predominant fentanyl (48.5%), fentanyl and heroin (20.0%), fentanyl and psychostimulants (12.8%), prescription opioid/undifferentiated (10.6%), and predominant cocaine (8.0%). Relative to predominant fentanyl, decedents in the fentanyl and heroin class and predominant cocaine class were more likely to be black (Ps < .05) whereas those in the fentanyl and methamphetamine class and prescription opioid/undifferentiated class were more likely to be white (Ps < .05). Females comprised a larger proportion of decedents in the fentanyl and heroin, predominant cocaine, and prescription opioid/undifferentiated classes (Ps < .05). Deaths in the predominant fentanyl class were more likely to occur in urban versus suburban environments (Ps < .05).

Conclusions: Findings diverge from previous research and national patterns highlighting the importance of local data for informing health care and policy in mid-sized and Midwest cities. Overdose prevention that addresses both intentional ingestion and unintentional ingestion of fentanyl with other substances, particularly stimulants, are warranted as its ubiquity in the drug supply persists.