Association of injury-related mortality with unique domains of social determinants of health across the urban-rural continuum

BACKGROUND: Social determinants of health impact outcomes after traumatic injury. Little is known regarding if and how this impact of social determinants of health in trauma varies across different geographic settings. Our objective was to evaluate whether social determinants of health associated with injury-related mortality vary based on geographic region. METHODS: We conducted a retrospective cohort study using the Pennsylvania Trauma Study Outcomes database merged with data from the Association for Healthcare, Research, and Quality social determinants of health database. Bootstrapped elastic net regression determined the association between risk-adjusted mortality and social determinants of health factors in urban, suburban, and rural areas. RESULTS: A total of 374,136 patients were included in the study (285,062 urban, 71,847 suburban, and 17,227 rural). Economic context and physical infrastructure were the most important domains for urban populations, whereas social context was the most important domain for suburban and rural populations. In urban populations, the increasing proportion of White race was most strongly associated with lower morality risk (coefficient: -0.045; 95% confidence interval: -0.044, -0.046), whereas income/poverty, transportation, and health insurance were the most common features associated with mortality. In suburban and rural communities, US born citizens were most strongly associated with lower mortality risk (coefficient: -0.024; 95% confidence interval: -0.023, -0.025), while demographics and housing were most commonly associated with mortality. CONCLUSION: The social determinants of health associated with mortality after injury vary across geographic settings. This may inform risk stratification and more effectively target policy and community interventions by geography to reduce the burden of injury.