Correlates of experiencing and witnessing non-fatal opioid overdoses among individuals accessing harm reduction services in Philadelphia, Pennsylvania.

: With the dramatic increase in overdose deaths in the United States, layperson overdose education and naloxone distribution (OEND) programs serve a critical role in preventing opioid overdose fatality. This study examines associations for witnessing an opioid overdose or experiencing a non-fatal opioid overdose to identify new opportunities for expansion of OEND programs. : Cross sectional surveys were administered at the sole needle and syringe exchange program in Philadelphia, PA. Bivariate and multivariable logistic regression analyses were conducted to examine associations for witnessing an opioid overdose or experiencing a non-fatal opioid overdose in the previous 12 months. : In total, 370 individuals were identified as using opioids in the previous three months and included in the study. Factors associated with experiencing a non-fatal opioid overdose were unstable housing (aOR: 2.16; 95% CI: 1.12-3.99), recent incarceration (aOR: 2.34; 95% CI: 1.41-3.89), co-use of opioids and benzodiazepines (aOR: 2.04; 95% CI: 1.22-3.41), co-use of heroin and cocaine (aOR: 1.69; 95% CI: 1.04-2.75), drug injection (aOR: 4.25; 95% CI: 1.90-9.54), inpatient detoxification history (aOR: 2.33; 95% CI:1.27-4.43), and witnessing an overdose in the previous 12 months (aOR: 2.51; 95% CI: 1.02-6.13). Factors associated with witnessing an overdose were unstable housing (aOR: 5.14; 95% CI: 2.57-10.28), recent incarceration (aOR: 2.88; 95% CI: 1.24-6.74), and a history of being trained to use naloxone (aOR: 3.39; 95% CI: 1.63-7.04). Findings presented here show characteristics of those most likely to witness an overdose or experience a non-fatal overdose who could be served by expansion of OEND programs.