title: Neighborhood-Level and Spatial Characteristics Associated with Lay Naloxone Reversal Events and Opioid Overdose Deaths.
abstract: There were over 23,000 opioid overdose deaths in the USA in 2013, and opioid-related mortality is increasing. Increased access to naloxone, particularly through community-based lay naloxone distribution, is a widely supported strategy to reduce opioid overdose mortality; however, little is known about the ecological and spatial patterns of the distribution and utilization of lay naloxone. This study aims to investigate the neighborhood-level correlates and spatial relationships of lay naloxone distribution and utilization and opioid overdose deaths. We determined the locations of lay naloxone distribution sites and the number of unintentional opioid overdose deaths and reported reversal events in San Francisco census tracts (n = 195) from 2010 to 2012. We used Wilcoxon rank-sum tests to compare census tract characteristics across tracts adjacent and not adjacent to distribution sites and multivariable negative binomial regression models to assess the association between census tract characteristics, including distance to the nearest site, and counts of opioid overdose deaths and naloxone reversal events. Three hundred forty-two opioid overdose deaths and 316 overdose reversals with valid location data were included in our analysis. Census tracts including or adjacent to a distribution site had higher income inequality, lower percentage black or African American residents, more drug arrests, higher population density, more overdose deaths, and more reversal events (all p < 0.05). In multivariable analysis, greater distance to the nearest distribution site (up to a distance of 4000 m) was associated with a lower count of Naloxone reversals [incidence rate ratio (IRR) = 0.51 per 500 m increase, 95% CI 0.39-0.67, p < 0.001] but was not significantly associated with opioid overdose deaths. These findings affirm that locating lay naloxone distribution sites in areas with high levels of substance use and overdose risk facilitates reversals of opioid overdoses in those immediate areas but suggests that alternative delivery methods may be necessary to reach individuals in other areas with less concentrated risk.
authors.affiliation: San Francisco Department of Public Health, 25 Van Ness Avenue, Ste. 500, San Francisco, CA, 94102, USA. chris.rowe@sfdph.org.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rowe
authors.affiliation: San Francisco Department of Public Health, 25 Van Ness Avenue, Ste. 500, San Francisco, CA, 94102, USA.|University of California, San Francisco, 500 Parnassus Avenue, San Francisco, CA, 94143, USA.
authors.forename: Glenn-Milo
authors.initials: GM
authors.lastname: Santos
authors.affiliation: University of California, San Francisco, 500 Parnassus Avenue, San Francisco, CA, 94143, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.affiliation: Drug Overdose Prevention and Education Project, Harm Reduction Coalition, 1440 Broadway, Suite 902, Oakland, CA, 94612, USA.
authors.forename: Eliza
authors.initials: E
authors.lastname: Wheeler
authors.affiliation: University of California, San Diego, 9500 Gilman Drive, La Jolla, California, CA, 92093, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Davidson
authors.affiliation: San Francisco Department of Public Health, 25 Van Ness Avenue, Ste. 500, San Francisco, CA, 94102, USA.|University of California, San Francisco, 500 Parnassus Avenue, San Francisco, CA, 94143, USA.
authors.forename: Philip O
authors.initials: PO
authors.lastname: Coffin
mesh_terms: D000701:Analgesics, Opioid / Q000506:poisoning*; D062787:Drug Overdose / Q000188:drug therapy* / Q000401:mortality; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006801:Humans; D009270:Naloxone / Q000008:administration & dosage / Q000627:therapeutic use*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D009293:Opioid-Related Disorders / Q000188:drug therapy; D012111:Residence Characteristics; D012495:San Francisco / Q000453:epidemiology; D012959:Socioeconomic Factors; D062206:Spatial Analysis; D014504:Urban Health
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009270:Naloxone
keywords: Naloxone; Opioids; Overdose; Spatial analysis