ABSTRACT
BACKGROUND: Previous work has shown socioenvironmental factors can influence firearm injury. Milwaukee County, Wisconsin is a diverse midwestern county with historic disinvestment in marginalized communities yielding stark segregation along racial and ethnic lines. It is also one of the many U.S. counties burdened by surging firearm injuries. The differences among communities within Milwaukee County provides a unique opportunity to explore the intersection of socioenvironmental factors that may affect clinical outcomes and geospatial patterns of firearm injury. METHODS: The trauma registry from the regional adult level 1 trauma center was queried for patients who sustained a firearm-related injury from 2015 to 2022 (N = 2402). The Social Vulnerability Index (SVI) ranking was derived using patient residence addresses to evaluate its association with traumatic injury clinical outcomes (i.e., in-hospital mortality, length of hospital stay, ICU or ventilator treatment, or injury severity score) and risk screening results for alcohol use disorder (AUD), posttraumatic stress disorder (PTSD), and depression. We evaluated hotspots of firearm injury density over time for patient residences and injury locations and distances between locations. A spatially lagged regression model tested the association between firearm injury density and SVI domains, alcohol outlet types, and park coverage. RESULTS: Most firearm injury patients were younger, male, racial or ethnic minorities from disadvantaged neighborhoods (SVI total; M = 0.86, SD = 0.15). SVI was not associated with any clinical outcomes. Of those screened, 12.9% screened positive for AUD and 44.5% screened at risk for PTSD, depression, or both. Hotspot analysis indicated consistent concentrations of firearm injury density. There were no differences in clinical outcomes between those injured inside or outside the home. Census tracts with lower socioeconomic status, greater off-premises and lower on-premises alcohol outlet density were associated with greater firearm injury density. CONCLUSIONS: In Milwaukee County, firearm injury patients are injured in and often return to the same disadvantaged neighborhoods that may hamper recovery. Results replicate and expand previous work and implicate specific socioenvironmental factors for intervention and prevention of firearm injury.
