The severely injured older patient: identifying patients at high risk for mortality using the Dutch National Trauma Registry

Purpose
The incidence of severely injured older trauma patients is increasing globally, portraying high mortality rates. Exploring the demographics and clinical outcomes of this subgroup is essential to further improve specialised care at the right place. This study was performed to identify severely injured older patients at high risk for mortality by examining their characteristics and identifying prognostic factors contributing to mortality.

Methods
A retrospective cohort study was conducted using data from the Dutch National Trauma Registry to identify all trauma patients aged 70 years and older from 2016 to 2022. Subgroup analyses for characteristics and outcomes were performed based on Injury Severity Score (ISS) 16-24 and ISS >= 25, as well as age groups of 70-79, 80-89 and >= 90 years. A logistic, backwards regression analysis was performed to identify predictors for mortality within each ISS groups.

Results
In total, 10,901 patients were included. The mean age was comparable between the ISS groups (80.48 +/- 6.8 vs. 80.54 +/- 6.6 years). The main trauma mechanisms in both the ISS 16-24 and ISS >= 25 were low energy falls and bicycle accidents. The head and thorax were the most frequently injured body regions, with a significantly higher proportion of severe head injuries in the ISS >= 25 group (32.6% vs. 73.4%). Mortality rates increased significantly with higher injury severity (13.9% vs. 48.9%) and advancing age (22.6% vs. 32.4% vs. 35.8%). The most significant predictors of mortality in the ISS 16-24 group were an increase in ASA score and a GCS 3-8 at arrival (OR for GCS: 7.2 (95% CI 5.7-9.1), AUC 0.76). Similarly, in the ISS >= 25 group, an increased ASA score and a GCS 3-8 at arrival were the most significant predictors of mortality as well (OR for GCS: 10.8 (9.1-12.9), AUC 0.79). Although increasing age was also associated with a higher risk of mortality in both ISS groups, its impact was less significant than the aforementioned variables.

Conclusion
Severe injuries in older patients are predominantly caused by low energy falls and bicycle accidents, leading to high mortality rates. A low GCS at arrival and high ASA scores are most strongly associated with an increased risk for mortality. Notably, despite the prevalence of severe injuries among the oldest patients, the proportion of intensive care unit admissions decreases markedly with age. This raises the question what feasible care for these often frail patients should comprise of and where this care should be provided, especially for those with severe pre-existent comorbidities.

Level of evidence and study type
Level III, prognostic/epidemiological.