Firearm incidents and cardiovascular disease mortality: A census-tract level study.

Firearm injury is a dire public health crisis in the United States. While its mental health impacts are well-documented, its associations with chronic disease outcomes, particularly at the contextual level, remain underexplored. This gap is especially important given that cardiovascular disease (CVD) is the leading cause of death in both Michigan and the U.S. overall. This study examines the association between census-tract-level firearm incidents and stress-related CVD mortality in Michigan. Using data from the Michigan Incident Crime Reporting System and mortality records from the Michigan Department of Health and Human Services, we analyzed intentional firearm incidents and CVD deaths across six counties from 2017 to 2021. Multilevel logistic regression was used to assess whether census-tract firearm incidents were associated with stress-related CVD mortality, adjusting for individual- and tract-level covariates. Tract-level firearm incidents were significantly associated with higher odds of stress-related CVD mortality. Specifically, each additional 10 firearm incidents per year within a census tract was linked to a 1.6 % increase in the odds of stress-related CVD death. This association remained significant after adjusting for individual factors (age, sex, race/ethnicity, education, tobacco use) and tract-level urbanicity and poverty. Given the high rates of firearm violence in some Michigan counties, residents in high-violence census tracts may face disproportionately greater cumulative risks of stress-related CVD mortality over time. These findings highlight the importance of considering firearm violence as a localized environmental factor of cardiovascular health and the need to account for multi-level factors and approaches to comprehensively understand and improve CVD outcomes.