Polysubstance Overdose Deaths in the Fentanyl Era: A Latent Class Analysis

To elucidate the main latent classes of substances detected among overdose decedents, and latent class associations with age, sex, race, and jurisdiction of death in Maryland.

We used toxicology data from the Office of the Chief Medical Examiner of Maryland for all decedents. We analyzed all cases of drug overdose deaths that occurred from 2016 to 2018 (N = 6566) using latent class analysis and regression.

Drug overdose deaths were concentrated in 2 of 24 counties in Maryland (Baltimore City and County). Fentanyl was involved in 71% of all drug overdose deaths, and the majority (76%) of these deaths included multiple substances. Three latent classes emerged: (1) fentanyl/heroin/cocaine (64%); (2) fentanyl/alcohol (18%); and (3) prescription drugs including opioids, benzodiazepines and antidepressants (18.0%). The fentanyl/heroin/cocaine class members were significantly younger (<30 years), female and White compared to the fentanyl/alcohol class, but more male and non-White than the prescription drugs class (all P < 0.05). Deaths in Baltimore City/County were more likely than in other locations to involve fentanyl/alcohol (P < 0.05).

The majority of fentanyl-involved overdose deaths in Maryland involved multiple substances, and several demographic and geographic differences in these patterns emerged. Geographically-targeted interventions that are tailored to reduce the harms associated with polysubstance use (including cocaine, alcohol, and prescription drugs) for different demographic groups are warranted.