Federal Firearm Licensee Rates and Suicide in Maryland, 2014 to 2019

Introduction: Federal firearm licensee density is associated with interpersonal firearm violence. Yet the role of Federal firearm licensees in firearm suicide remains understudied, even though firearms are the method used in more than half of suicides. This study tested associations between the spatial distribution of federal firearm licensees and firearm suicides in Maryland. Methods: Kernel density estimation measured federal firearm licensee and suicide rates at the census tract level (n=1,397), and SaTScan detected clusters of licensees and suicides. Choropleth maps compared visual associations between federal firearm licensee, firearm, and non-firearm suicide rates and clusters. Generalized estimating equations tested associations between Federal firearm licensee rates and clusters and the odds of using a firearm as the lethal means overall and after stratifying by biological sex. Data were obtained in 2020 and analyzed in 2020–2024. Results: The federal firearm licensee rate was associated with greater odds of firearm suicide overall (aOR=1.29, 95% CI=1.21, 1.38, p<0.001), for men (aOR=1.29, 95% CI=1.20, 1.39, p<0.001), and for women (aOR=1.26, 95% CI=1.07, 1.49, p=0.007). Suicide decedents in a census tract located in a federal firearm licensee cluster (vs not) had higher odds of firearm use overall (aOR=1.70, 95% CI=1.28, 2.27, p<0.001) and for men (aOR=1.67, 95% CI=1.22, 2.27, p=0.001), but not for women (aOR=1.65, 95% CI=0.81, 3.34, p=0.168). Conclusions: The federal firearm licensee rate and clusters were associated with firearm suicides and unrelated to the spatial distribution of non-firearm suicides. Prevention approaches that limit the number of these federal firearm licensees or alter their sales practices, such as federal firearm licensee zoning and land use provisions, advertising restrictions, or gun shop projects, may prevent firearm suicides.