Injuries/Violence
Spatial Analysis of Social Vulnerability and Firearm Injuries in King County, Washington, 2019–2023 Precious Esie* Precious Esie Jennifer Liu Myduc Ta Karyn Brownson Aley Joseph Pallickaparambil
Background: In the US, firearm injuries cluster geographically, often in low-income communities and communities of color. To assess the value of a composite measure to describe spatial disparities, we conducted an ecological analysis examining the association between CDC’s Social Vulnerability Index (SVI) (i.e., a percentile rank-based composite measure of social vulnerability) and firearm injuries in King County, Washington.
Methods: We used health reporting areas (HRAs) as the spatial unit of analysis (n=61), which generally correspond to neighborhoods or unincorporated areas of King County. HRA-level counts of firearm injuries, which include both fatal and non-fatal injuries of all intents combined (e.g., homicide, suicide, assault, unintentional), were based on King County Emergency Medical Services (EMS) responses during January 2019–June 2023. SVI was categorized into tertiles (low, moderate, and high). Bivariate choropleth maps between SVI and firearm injuries illustrated spatial associations. We quantified the magnitude of the association between SVI and rates (per 10,000 population) of firearm injuries using Bayesian spatial negative binomial regression.
Results: In bivariate choropleth maps, areas of high and low rates of firearm injuries were colocated with areas of high and low levels of SVI, respectively. In spatial models, HRAs categorized as high vulnerability had rates of firearm injuries approximately 3 times higher than HRAs categorized as low vulnerability (incidence rate ratio [IRR] = 2.96; 95% credible interval [95% CrI]: 1.98, 4.42). Rates were also higher in HRAs categorized as moderate vulnerability (IRR = 1.64; 95% CrI = 1.17, 2.31).
Conclusions: In King County, areas with high social vulnerability had higher rates of EMS responses to firearm injuries. SVI can help identify geographic areas for intervention and provide a framework toward better understanding which upstream factors might contribute to spatial disparities.
