Alcohol- and Drug-Related Mortality Among Adults Within and Outside the U.S.-Mexico Border Region

Although researchers and policy makers have often considered the U.S.-Mexico border region to be at high risk for substance use problems, epidemiological studies of this region have been hard to interpret because of their modest geographic coverage, reliance on self-report, and mixed results. The current study addresses limitations of existing studies and extends the knowledge base by comparing alcohol- and drug-related mortality in counties on versus off the border across all four U.S. border states.

Data were from the 2008-2017 Centers for Disease Control and Prevention WONDER Multiple Causes of Death data set, American Community Survey, and Rural Urban Continuum Codes, including all four border states. Spatial lag models tested differences across on- and off-border counties in total alcohol- and drug-related mortality ("total mortality"), alcohol-related mortality, and drug-related mortality.

In multivariate models, mortality rates were significantly higher in off- versus on-border counties for all three outcomes (ps < .05). Rates for total mortality, alcohol-related mortality, and drug-related mortality were 28%, 82%, and 30% higher, respectively, off versus on the border. Border effects were similar, excluding California; robust over time; and stronger for Latinx versus White decedents.

Results suggest a revised understanding of the border, revealing that residents of interior counties of border states are at highest risk of severe substance use consequences. Results are consistent with other research finding that border counties were protected against drug overdose deaths, particularly for Latinx residents.