Divergent risk factors for mortality in blunt trauma: comparison of urban and rural event locations and injury severity in a single level 1 trauma centre in South Korea

Trauma remains a leading cause of mortality worldwide. Among patients with blunt trauma, factors associated with in-hospital mortality may vary according to geographic and injury-specific characteristics. This study aimed to identify factors associated with in-hospital mortality among patients with blunt trauma treated at a Level 1 trauma centre in South Korea, with particular attention to differences based on trauma event location (urban vs. rural) and injury severity. This retrospective cohort study included 1,409 adult patients with blunt trauma admitted between January 2022 and December 2024. Multivariable logistic regression was performed to identify factors associated with in-hospital mortality in the overall cohort and in subgroups stratified by trauma event location (urban vs. rural) and injury severity (moderate injury: Injury Severity Score [ISS] 16–24; severe injury: ISS ≥ 25). The overall in-hospital mortality rate was 17.2%. In the total cohort, older age, lower Glasgow Coma Scale (GCS) score, higher ISS, severe head injury, and transfusion requirement were significantly associated with in-hospital mortality, whereas secondary transfer was inversely associated with mortality. In the urban subgroup, older age, hypertension, lower GCS score, higher ISS, transfusion, and secondary transfer were associated with mortality. In the rural subgroup, only lower GCS score and transfusion remained significant. In both the moderate- and severe-injury subgroups, older age, lower GCS score, higher ISS, and transfusion were associated with mortality. Secondary transfer was not significantly associated with mortality in either injury-severity subgroup. Surgical treatment was inversely associated with mortality only in the severe-injury subgroup. Factors associated with in-hospital mortality among patients with blunt trauma varied according to trauma event location and injury severity. These findings highlight the importance of considering regional healthcare context, anatomical injury severity, and early physiological compromise when planning trauma care. Trauma care strategies should incorporate early neurological and haemorrhagic indicators while accounting for regional access to definitive care. These findings may inform the development of more context-sensitive clinical and trauma system strategies.