How do contextual factors influence naloxone distribution from syringe service programs in the USA: a cross-sectional...

Naloxone is a medication that can quickly reverse an opioid overdose. Syringe service programs (SSPs) are community-based prevention programs that provide a range of evidence-based interventions in the USA, including naloxone distribution. Attributes of SSPs make them ideal settings for naloxone distribution-they have staff and delivery models that are designed to reach people who use drugs where they are. We assessed which outer and inner setting factors of SSPs were associated with naloxone distribution in the USA.

We surveyed SSPs in the USA known to the North American Syringe Exchange Network in 2019. Using the exploration, preparation, implementation and maintenance framework, we assessed inner and outer contextual factors associated with naloxone distribution among SSPs (n = 263 or 77% of SSPs). We utilized negative binomial regression to assess which factors were associated with the number of naloxone doses distributed and people receiving naloxone.

SSPs reported distributing 710,232 naloxone doses to 230,506 people in the prior year. Regarding outer setting, SSPs located in areas with high levels of community support had a higher level of naloxone distribution (aIRR = 3.07; 95% confidence interval (CI): 2.09-4.51; p < 0.001) and 110% (p = 0.022) higher rate of people receiving naloxone (aIRR = 2.10; 95% CI 1.46-3.02; p < 0.001) in the past 12 months. The legal status of SSPs and the level of need was not significantly associated with naloxone distribution. Regarding inner setting, SSPs with proactive refill systems (aIRR = 2.08; 95% CI 1.27-3.41; p = 0.004), greater number of distribution days (aIRR = 1.09 per day; 95% CI 1.06-1.11; p < 0.001) and older programs (aIRR = 1.06 per year; 95% CI 1.02-1.11; p = 0.004) were associated with higher levels of naloxone distribution. Also, SSPs with proactive refill systems (aIRR = 2.23; 95% CI 1.38-3.58; p = 0.001); greater number of distribution days (aIRR = 1.04; 95% CI 1.02-1.07; p < 0.001) and older programs (aIRR = 1.11; 95% CI 1.05-1.17; p < 0.001) were associated with a higher number of people receiving naloxone.

We identified outer and inner setting factors of SSPs that were associated with greater naloxone distribution. It is critical to ensure SSPs are adequately resourced to build community support for services and develop service delivery models that maximize naloxone distribution to address the nation's opioid overdose crisis.