Patterns of polysubstance use among people who use drugs on an American Indian reservation of a southern plains Tribal Nation

Polysubstance use is a key driver of overdose and infectious disease risk among people who use drugs (PWUD). Polysubstance use has not been well characterized in Indigenous American communities, which experience a disproportionate overdose burden. To characterize polysubstance use patterns among 192 PWUD on reservation lands of a southern Midwest tribe. We conducted a latent class analysis to identify profiles of polysubstance use in the past 6 months and assessed associations between latent classes, sociodemographic correlates, overdose, naloxone receipt, awareness of fentanyl test strips, and interest in using public health vending machines and syringe services programs (SSP). The average age of participants was 41. 55% self-identified as Indigenous, 59% were men, 27% were currently homeless, and 65% had experienced hunger due to a lack of food in the past 6 months. We identified three past 6-month polysubstance use patterns: Low Drug Use (48%), Methamphetamine and Opioid Use (11%), and Methamphetamine Only Use (41%). Methamphetamine and Opioid Use class was more likely to have experienced an overdose, received naloxone, and be interested in using a SSP than other classes. The Methamphetamine Only Use class was more likely to be interested in using a SSP than the Low Drug Use class. Classes did not significantly differ in fentanyl test strip awareness or public health vending machine interest. Expanding access to and indigenizing harm reduction services in tribal communities, including public health vending machines and SSPs, is a necessary step forward in addressing substance use disparities.