Polysubstance use in rural West Virginia: Associations between latent classes of drug use, overdose, and take-home naloxone

Background: Rural communities in the United States have been disproportionately affected by the opioid crisis. Little research has explored the relationship between polysubstance use and overdose experiences among people who inject drugs (PWID) in rural communities. We sought to identify classes of polysubstance drug use among rural PWID and evaluate the associations between polysubstance drug use classes, recent overdose experiences, and receipt of take-home naloxone (THN). Methods: We surveyed 420 PWID (June-July 2018) who had injected drugs in the previous 6 months in Cabell County, West Virginia. Participants were recruited from the local syringe services program and through street-based recruitment. We conducted a latent class analysis using 9 measures of injection and non-injection drug use and tested for associations with having experienced an overdose in the past 6 months and having received THN in the past 6 months. Results: We identified four substance use classes in our sample: polydrug/polyroute use (35.0% of the sample), polyroute stimulant/injection opioid use (33.3%), polyroute stimulant use (20.3%), and injection opioid use (11.3%). Overall, 42.6% of the sample had experienced an overdose in the past 6 months. The classes differed in terms of overdose (χ=91.53, p<0.001), with the polydrug/polyroute use class having the highest probability of overdose and the polyroute stimulants class having the lowest. Only 46.5% of participants had received THN, and probabilities differed between classes (χ=21.93, p<0.001). The polyroute stimulants/injection opioid use and polydrug/polyroute use classes had the highest levels of THN receipt while the polyroute stimulants use class had the least. Conclusion: Among rural PWID in West Virginia, polysubstance use was prevalent and associated with overdose and THN acquisition. These analyses demonstrate the importance of scaling up naloxone distribution in rural settings. Overdose prevention initiatives are reaching persons at high risk of overdose, but expansion of services is needed.