Mortality Rates for Substance Use Disorders, Intentional Injuries Vary Widely By County

Overall national mortality rates decreased for alcohol use disorders, self-harm, and interpersonal violence in the United States between 1980 and 2014, despite wide variation across counties. During the same period, both national and county mortality rates increased for drug use disorders. Results from this study were reported in JAMA.

Intentional injuries (self-harm and interpersonal violence) and substance use (alcohol use and drug use) remain public health challenges nationwide. However, regional and county-level geographic variations in mortality rates demand further scrutiny to best combat disability and early mortality on a local level and to ease the financial burden of these 4 disorders on the healthcare system.

For this study, investigators examined redacted death records and census information, along with the Human Mortality Database. They calculated age-standardized mortality rates on a county level in the United States (N=3110) between 1980 and 2014, specifically examining rates for the 4 conditions mentioned here.

From 1980 to 2014, there were 2,848,768 mortalities attributed to substance use disorders or intentional injuries in the United States. National mortality rates for self-harm (n=1,289,086), interpersonal violence (n=760,749), and alcohol disorders (n=256,432) all decreased during this period, by 6.0%, 44.9%, and 8.1%, respectively. Mortality rates for drug use disorders (n=542,501) increased by 618.3% nationwide.

On a county level, drug use disorder fatalities increased across the board, with all 3110 counties seeing upticks, although there was substantial variation among them, with relative increases ranging from 8.2% to 8369.7%. For the other 3 categories, there were wide variations across counties and regions with respect to mortality rates, with some decreasing and others increasing.

Geographic mortality inequalities, both absolute and relative, were reduced over this time for alcohol use disorders and interpersonal violence; but they were substantially expanded for self-harm and drug use disorders.

The authors identified the use of small-area estimation methods as a study strength that improved on previous efforts.

Study limitations included using data sources that are subject to error, lack of validation of redistribution algorithms, noninclusion of redistribution uncertainty in mortality rate confidence intervals, and tendency for small-area methods to underestimate true variability.

This investigation confirmed widespread differences in substance use and intentional injury mortality rates among US counties. Understanding the temporal and spatial variations that exist regarding these 4 causes of death, and examining epidemiological trends, is essential for all clinicians, public health officials, and policy makers who wish to maximize local effect via optimal resource allocation.

Reference

Dwyer-Lindgren L, Bertozzi-Villa A, Stubbs RW, et al. Trends and patterns of geographic variation in mortality from substance use disorders and intentional injuries among US counties, 1980-2014. JAMA. 2018;319(10):1013-1023.