Trauma undertriage at a University Hospital in North Norway: the need to look beyond mechanism of injury

Background Early multidisciplinary management through trauma team activation (TTA) improves outcomes for severely injured patients. Previous studies at the University Hospital of North Norway (UNN) Tromsø conducted in 2006 and 2013, using Injury Severity Score (ISS) ≥ 16 as reference, found high rates of undertriage at 32% and 28% respectively. The aim of this study was to assess the current undertriage at UNN Tromsø using both ISS ≥ 16 and the New Injury Severity Score (NISS) ≥ 16 as reference. Methods We retrospectively reviewed trauma patients admitted to UNN Tromsø in 2018 and 2023. The study included all patients met with TTA as well as all severely injured patients that did not receive TTA during the period. Data were obtained from the local trauma registry and electronic medical records. Undertriage was defined as patients with ISS ≥ 16 and no TTA, and NISS ≥ 16 and no TTA. Results A total of 527 trauma patients were included. Undertriage based on ISS was 15% overall for 2018 and 2023. When NISS ≥ 16 was applied, the undertriage increased to 18% (31/171). A total of 63% of undertriaged patients fulfilled one or more national TTA criteria but was not admitted with TTA. Low-energy falls were the predominant mechanism of injury (73%) among undertriaged patients. A total of 70% of undertriaged patients had single region injuries, and 40% had organ failure. Conclusions The undertriage rate at UNN Tromsø was 15% in 2018 and 2023, still exceeding the recommended level of < 5% according to American College of Surgeons-Committee on Trauma. Undertriage appears largely related to the system’s non-compliance with trauma criteria, and injuries sustained in low-energy trauma mechanisms. Use of NISS identifies a larger group of potentially undertriaged patients, including more patients with organ failure who may benefit from TTA.