Gun violence is an escalating national crisis that shapes overall levels of population health including average life expectancy. Crucially, in order to effectively address this crisis, it is imperative that we identify its root social causes, which may include social determinants of health (SDoH) such as income disparities and social mobility, and that we modify these root causes through corresponding policies. While a handful of SDoH have been shown to predict gun homicides and suicides, important questions remain about which SDoH are root social drivers i.e., have the greatest impacts. Despite increasing calls for comparative assessments and comprehensive approaches to unpack and address the root causes?the social determinants?of gun violence, we lack knowledge on the firearm mortality burden associated with modifying SDoH and SDoH-related policies, including by using multilevel, longitudinal data and quasi-experimental methods that favor causal inference. Furthermore, we have yet to establish which subpopulations are most affected by SDoH. Given this information, there are critical needs to accurately estimate SDoH impacts, including by subpopulation; and to translate these estimates into population health metrics that may serve as priority-setting tools. Not addressing these critical needs will hinder the development of policies to more effectively reduce firearm mortality burden and inequities. Our overall objective is to use quasi-experimental approaches to provide the first comparative assessment evidence base on the social drivers of the gun homicide and suicide epidemics. We will accomplish our overall objective by pursuing the following specific aims using data on 3.4 million adults from the nationally- representative sample of the Mortality Disparities in American Communities Study, linked to SDoH measures by area of residence and containing death information from national mortality database linkages:
Aim 1) To determine which SDoH and SDoH-related policies most strongly predict firearm homicides and suicides in adults. To strengthen causal inference, we will implement robust quasi-experimental and epidemiologic approaches including difference-in-difference, propensity score, and changes-in- changes analysis;
Aim 2) To identify which subpopulations (defined by race/ethnicity, SES, and urban/rural residence) are most vulnerable to influences of SDoH and SDoH-related policies on firearm homicides and suicides;
and Aim 3) To ascertain which SDoH and SDoH-related policies if modified are expected to yield the greatest reductions in firearm homicide and suicide burden, both nationally and by subpopulation. Regarding outcomes, we will identify the most promising SDoH on which to intervene to yield improvements in adult firearm mortality burden. We will further establish how differential vulnerabilities by subpopulations may explain disparities. By translating estimates into population health metrics, we expect that our project will have high translational impact through guiding policymakers' evidence-based decisions about policies to more effectively reduce the burden of and inequities in mortality from gun violence in America.
(PUBLIC HEALTH RELEVANCE) Using a large, nationally-representative sample of 3.4 million Americans, this study will provide the first comparative assessment evidence base on the firearm homicide and fatal suicide burden impacts of modifying key social determinants of health (SDoH) and SDoH-related policies in adults, hence directly responding to NIH and IOM calls for comparative assessments in prevention research. We will further establish how vulnerabilities to effects by subpopulation may explain disparities. Over the long term, by translating our estimates into population-wide firearm mortality burden measures from modifying SDoH and SDoH-related policies, we expect that our project will have high translational impact through guiding policymakers' evidence-based decisions to reduce the burden of and disparities in firearm mortality among Americans.
