Narrative minireview of the spatial epidemiology of substance use disorder in the United States: Who is at risk and where?

Abstract

Drug overdose is the leading cause of death by injury in the United States. The incidence of substance use disorder (SUD) in the United States has increased steadily over the past two decades, becoming a major public health problem for the country. The drivers of the SUD epidemic in the United States have changed over time, characterized by an initial heroin outbreak between 1970 and 1999, followed by a painkiller outbreak, and finally by an ongoing synthetic opioid outbreak. The nature and sources of these abused substances reveal striking differences in the socioeconomic and behavioral factors that shape the drug epidemic. Moreover, the geospatial distribution of the SUD epidemic is not homogeneous. The United States has specific locations where vulnerable communities at high risk of SUD are concentrated, reaffirming the multifactorial socioeconomic nature of this epidemic. A better understanding of the SUD epidemic under a spatial epidemiology framework is necessary to determine the factors that have shaped its spread and how these patterns can be used to predict new outbreaks and create effective mitigation policies. This narrative minireview summarizes the current records of the spatial distribution of the SUD epidemic in the United States across different periods, revealing some spatiotemporal patterns that have preceded the occurrence of outbreaks. By analyzing the epidemic of SUD-related deaths, we also describe the epidemic behavior in areas with high incidence of cases. Finally, we describe public health interventions that can be effective for demographic groups, and we discuss future challenges in the study and control of the SUD epidemic in the country.

Keywords: Disease mapping; Risk factors; Spatial epidemiology; Spatial statistics; Substance use disorder.

Figure 1

Death rates (number of deaths per 100000 individuals in 2019) from opioid overdoses in the world. Source: IHME, Global Burden of Disease, 2019 (https://www.healthdata.org/gbd/2019). Maps were generated using ArcGIS Pro. 2.8[86].

Figure 2

Spatial distribution of the substance use disorder related mortality. A: The general population; B: White population; C: Black population in the contiguous United States. Maps were generated using ArcGIS Pro. 2.8[86].

Figure 3

Temporal dynamics of the opioids overdose epidemic in Ohio (2010–2016) in the total population and in the most affected populations. The highest prescription opioid overdose mortality rates were found in the White male population aged 30-39 years, with 125 deaths/100000 persons, followed by Black males of same age, with 57 deaths/100000 persons compared to the 29 deaths/100000 persons for the total population in 2016. Dashed lines illustrated the fitted exponential curve for each growth rate. Plot was created using the software environment R[87].

Figure 4

Spatial distribution of the opioid overdose epidemic in Ohio. A: Spatial distribution of opioids overdose mortality rate in Ohio; B: Bivariate map illustrating counties with high opioid overdose mortality rate (purple) and high density of pharmacies (blue). Counties in dark color have both high opioids overdose mortality and density of pharmacies dispensing naloxone. Maps were generated using ArcGIS Pro. 2.8[86].