A mixed methods study to inform fatal overdose prevention in San Diego, California: Perspectives from people who use drugs.

Background: In the United States, community overdose education and naloxone distribution (OEND) programs have demonstrated efficacy in reducing opioid-related mortality. OEND programs have expanded across San Diego County, California, but differential naloxone accessibility among people who use drugs (PWUD) has not been assessed. We examined factors that shape individual naloxone accessibility in San Diego.

Methods: We employed a convergent parallel mixed methods design using surveys (n = 194) and qualitative interviews (n = 20). Ordinal logistic regression examined factors associated with individual naloxone accessibility (i.e., the frequency with which participants could access naloxone within five minutes, categorized as never, sometimes, or always). Qualitative interviews explored participant perceptions of naloxone accessibility and whether and how they maintained naloxone. We organized multilevel findings into a modified social-ecological model.

Results: In quantitative and qualitative samples, participants were majority male (72 % and 70 % respectively), non-White race/ethnicity (55 % and 75 %), with an average age around 42 years. In the quantitative sample, 24 % never had personally accessible naloxone, 52 % sometimes did, and 24 % always did. Factors independently associated with individual naloxone accessibility were female gender (Adjusted Odds Ratio [AdjOR]: 2.51, 95 % Confidence Interval [CI]: 1.31-4.85), monthly income <$500 (AdjOR: 0.42, 95 %CI:0.19, 0.90), witnessing an overdose (AdjOR: 3.51, 95 %CI:1.67-7.55), and knowing where to get free naloxone (AdjOR: 3.44, 95 %CI: 1.79-6.75). Qualitative data suggested that naloxone was generally easy to acquire in San Diego due to community harm reduction outreach and mutual aid among peers, albeit community barriers including distance to harm reduction providers and frequent relocation/displacement for those experiencing homelessness. Individual attitudes toward overdose risk, naloxone, and community responsibility contributed to varied individual naloxone accessibility.

Conclusions: This study highlights multilevel factors influencing individual naloxone accessibility among people who use drugs in San Diego, emphasizing the importance of harm reduction outreach and peer-to-peer support. We identified opportunities for interventions that address both individual attitudes and community-level barriers to improve naloxone accessibility.