Spatiotemporal Trends in Three Smoothed Overdose Death Rates in US Counties, 2012–2020

Abstract

From 2019 to 2020, the number of drug overdose deaths in the US increased by 31%. During the same period, the rate of drug overdose deaths involving synthetic opioids other than methadone, including illicitly manufactured fentanyl, fentanyl analogs, and tramadol, increased by 56% (1). The number of overdose deaths involving psychostimulants (mostly methamphetamine) has also risen, with a 5-fold increase in these deaths from 2012 to 2018 (2). The rise in opioid overdose deaths has occurred in 4 distinct waves (1–3). The first wave began in the 1990s and peaked around 2017 with the increase in overdose deaths involving prescription opioids (ie, natural opioids, semisynthetic opioids, and methadone). The second wave began in 2010 with increases in overdose deaths involving heroin, peaking in 2017. The third wave of overdose deaths began in 2013 with the rise in synthetic opioids (mainly illicitly produced fentanyl and fentanyl analogs) added to the heroin supply. Data suggest that we are now entering a fourth wave of overdose deaths characterized by psychostimulants with abuse potential (hereinafter, psychostimulants), which includes methamphetamine (2). Throughout these waves, the changing toxicity of the illicit drug market has influenced the geographic spread of overdose deaths (2,4,5). We used geospatial techniques to explore county-level spatiotemporal patterns of overdose death rates during the third and fourth waves of the opioid epidemic in the contiguous US from 2012 to 2020. We describe and visualize the results of spatial empirical Bayesian smoothed overdose death rates for 3 types of overdoses. County-level spatiotemporal patterns in synthetic opioid and psychostimulant– related overdose deaths have not been systematically visualized together but are potentially useful to public health officials and researchers seeking to improve health and identify potential areas of concern