Associations between Circumstances Surrounding Overdose and Underlying Classes of Polysubstance Overdose Deaths.

Background: The overdose crisis is worsening, with polysubstance overdose deaths involving psychostimulants increasing in the U.S. Substance-specific prevention and intervention activities may not be as effective for polysubstance use, so we sought to classify substances used among overdose decedents to identify unique factors related to these classes.

Methods: We used data from the Nevada State Unintentional Drug Overdose Reporting System, Jan 2019-Jun 2021, which comes from death certificates, coroner/medical examiner reports, and postmortem toxicology. Latent class analysis, multinomial logistic regression, and Chi-squared tests determined underlying drug use classes, differences in characteristics and circumstances surrounding overdose, and assessed relationships between circumstances and drug use classes.

Results: We identified four latent classes: (1) prescription drugs (19.1%), (2) predominately methamphetamine (31.4%), (3) multi-drug (28.9%), and (4) opioid and stimulant (20.6%). Compared to other classes, the prescription drug class had a higher percentage of female decedents, from rural counties, with mental health diagnoses, who died at home. The predominately methamphetamine class had a higher percentage of decedents experiencing homelessness. The multi-drug use class had higher percentage of younger and Hispanic decedents. Those in the opioid and stimulant class had higher odds of being recently released from an institutional setting, compared to the multi drug class.

Conclusions: These underlying classes were associated with several characteristics and circumstances that can prove useful for prevention, treatment, and harm reduction agencies when designing programs and interventions to target specific groups of people at-risk for drug overdose.