Burned by Inequity: How Social and Geographic Disparities Shape Burn Mortality

Introduction: Burn injuries are a persistent public health burden, often complicated by prolonged hospitalizations and significant mortality. While clinical predictors such as age, total body surface area (TBSA), and inhalation injury are well-established risk factors, social determinants of health (SDOH), particularly in rural and underserved regions, are increasingly recognized as contributors to patient outcomes. This study investigates whether commonly used national geospatial indices adequately capture the social vulnerability of rural populations.


Methods: This retrospective cohort study analyzed 1,841 adult burn patients treated at a regional burn center serving rural Texas and New Mexico from 2019 to 2024. Patients were stratified by ZIP code-linked SDOH metrics, including SES, the CDC Social Vulnerability Index (SVI), the FEMA National Risk Index (NRI), and the Area Deprivation Index (ADI). Univariate and multivariable logistic regressions assessed associations between these variables and in-hospital mortality, adjusting for age, burn size (second- and third-degree TBSA), inhalation injury, and prevalent comorbidities. Interaction models explored whether SES modified the effect of clinical predictors on mortality.


Results: Socioeconomic deprivation emerged as a strong, independent predictor of mortality. Patients in the most deprived SES quartile had more than twice the odds of in-hospital death compared to those in the least deprived quartile (adjusted OR = 2.26, p = 0.021). This effect persisted after adjustment for significant clinical variables. In contrast, the SVI and NRI, while associated with mortality in univariate analyses, did not retain significance in multivariable models. Interaction analyses showed no evidence that SES modified the impact of clinical severity.


Conclusions: Among burn patients in a largely rural catchment area, ZIP code–based SES more accurately predicts in-hospital mortality than widely used national vulnerability indices. These findings emphasize the limitations of aggregate indices like the SVI and NRI in capturing rural risk and highlight the need for a rural-sensitive social risk metric. Integrating SES into clinical workflows could improve prognostication, resource allocation, and health equity in burn care for rural patients.