Identifying the severely injured benefitting from a specific level of trauma care in an inclusive network:A multicentre retrospective study

Introduction: Defining major trauma (MT) with an Injury Severity Score (ISS) > 15 has limitations. This threshold is used for concentrating MT care in networks with multiple levels of trauma care. Objective: This study aims to identify subgroups of severely injured patients benefiting on in-hospital mortality and non-fatal clinical outcome measures in an optimal level of trauma care. Methods: A multicentre retrospective cohort study on data of the Dutch National Trauma Registry, region South West, from January 1, 2015 until December 31, 2019 was conducted. Patients ≥ 16 years admitted within 48 h after trauma transported with (H)EMS to a level I trauma centre (TC) or a non-level I trauma facility with a Maximum Abbreviated Injury Scale (MAIS) ≥ 3 were included. Patients with burns or patients of ≥ 65 years with an isolated hip fracture were excluded. Logistic regression models were used for comparing level I with non-level I. Subgroup analysis were done for MT patients (ISS > 15) and non-MT patients (ISS 9–14). Results: A total of 7,493 records were included. In-hospital mortality of patients admitted to a non-level I trauma facility did not differ significantly from patients admitted to the level I TC (adjusted Odds Ratio (OR): 0.94; 95% confidence interval (CI) 0.68–1.30). This was also applicable for MT patients (OR: 1.06; 95% CI 0.73–1.53) and non-MT patients (OR: 1.30; 95% CI (0.56–3.03). Hospital and ICU LOS were significantly shorter for patients admitted to a non-level I trauma facilities, and patients admitted to a non-level I trauma facility were more likely to be discharged home. Findings were confirmed for MT and non-MT patients, per injured body region. Conclusion: All levels of trauma care performed equally on in-hospital mortality among severely injured patients (MAIS ≥ 3), although patients admitted to the level I TC were more severely injured. Subgroups of patients