Trauma disparities occur upstream from hospitals: Neighborhood social vulnerability predicts incidence of various traumatic injuries but not case fatality.

Abstract

Trauma is a complex disease process often affecting the most vulnerable members of society. This cross-sectional study aims to identify the relationship between incidence and case fatality rate of injury with the Social Vulnerability Index (SVI), a composite score of community disparity. A convenience sample of six State Inpatient Databases from 2016, provided by the Healthcare Cost Utilization Project, was generated for patients older than 18 years with specific International Classification of Diseases, Tenth Revision , codes for external cause of injury. Individual ZIP codes were converted to census tracts, and SVI scores were assigned to each census tract divided each admission into an SVI quintile. Multivariable Poisson regression was used to assess association between incidence of traumatic events, case fatality, and SVI quintiles, adjusted for age, sex, state, and new Injury Severity Score. A total of 396,209 unique hospital admissions were included in the cohort. Injury from fall was the most common trauma, occurring in 308,280 admissions (77.8%). Proportionally, the highest SVI quintile (most vulnerable) experienced the most traumatic events across all injury categories. In those who experienced assault, the highest SVI quintile had over eight times greater incidence of injury compared with the lowest quintile (incidence rate ratio, 8.92; p < 0.001). The association of higher SVI and incidence of injuries persisted across all categories after adjusting for age, sex, and state. There was no meaningful association between case-fatality rate and SVI quintile in any traumatic injury category, before or after adjustment for Injury Severity Score, except for when age adjustment was removed from the model. Populations from more socially vulnerable neighborhoods experience traumatic events at higher rates than those living in low SVI neighborhoods. However, community social vulnerability was not associated with a clinically significant difference in in-hospital case-fatality rate, except when age adjustment was removed from the model. Understanding how the most vulnerable populations experience traumatic events differently can inform policy and guide targeted upstream preventative measures within vulnerable communities. Prognostic and Epidemiologic; Level III.