The Geographic Distribution of Fentanyl-Involved Overdose Deaths in Cook County, Illinois

Abstract

Objectives. To contrast the geographic distribution of fentanyl-involved and non-fentanyl-involved fatal overdoses between 2014 and 2018 in Cook County, Illinois.Methods. We conducted a spatial analysis using locations of fentanyl-involved fatal overdoses (n = 1433) compared with nonfentanyl opioid and polydrug fatal overdoses (n = 1838) collected through the Cook County Medical Examiner's Office from 2014 to 2018. We also used logistic regression to test significant individual- and neighborhood-level covariates.Results. Fentanyl overdoses geographically clustered more than nonfentanyl overdoses, and this difference was statistically significant. One area in particular showed significantly elevated risk for fentanyl overdoses (P < .05) located in 2 specific neighborhoods of Chicago. The odds of a fentanyl-involved overdose were significantly increased for men, Blacks, Latinos/as, and younger individuals. Neighborhood deprivation score was the only significant neighborhood-level predictor (odds ratio = 1.11; 95% confidence interval = 1.07, 1.17).Conclusions. Fentanyl-involved fatal overdoses follow a distinct geographic distribution associated with resource deprivation in neighborhoods where they occur. This suggests an evolving bifurcated drug market, with drug markets in resource-deprived neighborhoods disproportionately likely to include fentanyl.

FIGURE 1—

Difference in Fentanyl and Nonfentanyl Overdoses K Functions With Confidence Bands (Dashed) and Distance in Miles: Cook County, Illinois, 2014–2018 Note. Solid line indicates differences; dashed lines indicate confidence intervals, within which the null hypothesis would not be rejected.

FIGURE 2—

Map of Kernel Intensity Ratio Estimates Showing Significant Local Differences in Fentanyl and Nonfentanyl Overdose Intensities: Cook County, Illinois, 2014–2018 Note. Lighter grays indicate areas of elevated fentanyl overdoses compared with nonfentanyl overdoses. Dashed line represents the significant areas of log relative risk at P < .05. See Figure D, available as a supplement to the online version of this article at http://www.ajph.org, for color version.