Quantifying the size and characteristics of a population of people who use drugs on the reservation lands of a tribal nation in the southern plains (USA).

Abstract

Background: Reversing trends in substance use-related health inequities among Indigenous Peoples requires investments in epidemiological research anchored in community-based participatory research (CBPR) methodologies. There is scarce literature that describes how to implement population estimation methods on American Indian reservation lands.

Objective: This research describes how we leveraged CBPR throughout the implementation of a population estimation study conducted in collaboration with a Tribal Nation in the southern plains to quantify the size and characteristics of persons with histories of illicit substance use on reservation lands.

Methods: We used the capture and recapture population estimation methodology in April-May 2023 to estimate the size of the population of people who used illicit substances in the past six months in a county within the collaborating tribe's jurisdiction. Participant recruitment occurred in areas where people who use drugs were known to congregate. Participants completed a survey that included measures pertaining to sociodemographics, substance use, harm reduction, overdose, sexual health, and cultural factors.

Results: In total, N = 501 surveys were completed by unique persons who had used illicit substances in their lifetime. A large proportion had injected drugs in the past six months or greater than six months ago (19.6% and 31.7%, respectively). There were N = 210 persons who reported having used illicit substances by at least one route of administration within the last six months. We estimated that there were 419 (95% confidence interval = 277, 562) adults who had recently used an illicit substance in the county where the study occurred.

Conclusions: This study demonstrates that population estimation methodologies can be integrated with community-based participatory research approaches to quantify the size of populations of people who use drugs. Future work should be conducted to understand the degree to which population-level needs evolve over time and in response to local initiatives.