Accuracy of the Norwegian trauma protocol. An observational population study from South-Western Norway

The Norwegian trauma plan was established in 2007 and renewed in 2017 defining national trauma team activation (TTA) criteria. Norwegian studies validating the performance of previous TTA protocols have found overtriage and undertriage to be out of line with the quality indicators set in the national trauma plan, but studies have not yet been published validating the new TTA protocol.

This was a registry study of a prospectively maintained database in the period from 01/01/2018 to 12/31/2020. Data were collected from the Trauma Registry including prehospital documents. A total of 1519 patients were eligible, of which 95 were excluded, yielding a study population of 1424 patients. All patients were evaluated for a total of 29 criteria in four criteria groups: 1 Physiology, 2 Anatomical injury, 3 Mechanism of injury, and 4 Special considerations. Overtriage, undertriage, sensitivity and positive predictive value (PPV) were estimated for the current and alternative TTA protocols, criteria groups, and single criteria.

The current Norwegian TTA protocol involving criteria groups 1-3 had a total sensitivity of 84.8 %, hence an undertriage of 15.2 % (95 % confidence interval, 11.1-20.3 %), and PPV of 19.2 % hence an overtriage of 80.8 % (78.3-83.1 %). Patients 60 years and older had an undertriage of 21.6 %, whilst patients under 60 years of age had an undertriage of 11.2 %. A TTA protocol including criteria group 4 as well yielded a lower undertriage (5.6 %) without significantly increasing overtriage (81.7 %), and a TTA protocol with criteria group 4 replacing group 3 yielded an undertriage of 7.4 % and an overtriage of 81.0 %. Criteria group 3 Mechanism of injury was the criteria group with the most overtriage, at 95 %. Patients that did not meet any criteria had a similar overtriage of 94 %.

Both overtriage and undertriage are out of line with the goals set in the Norwegian trauma plan. Undertriage is often caused by older patients that do not fulfill the trauma criteria in the current TTA protocol. Mechanism of injury increases overtriage but does not reduce undertriage. The TTA protocol could be improved by changing the composition of criteria groups, removal of single criteria with low PPV, and by better compliance to the existing criteria.