An adequate Mass-Casualty Incident (MCI) triage system is essential to provide the best possible health care to the greatest number of affected people and to optimize the management of the available resources in the context of a MCI.

In February 2022, Disaster Medicine Service 118 of Regione Piemonte adopted a new 5-color code-MCI triage system and Emergency Medical System (EMS) personnel was trained through a 3-hours-distance learning course. 515 medical doctors and nurses attended the course and completed the final test (triaging of 50 computer-based simulated patients/cases). Their performance was compared to intended triage designations. We collected the data and conducted a descriptive observational study.

A total of 25.750 evaluations were carried out: 1.030 white cases, 6.180 green cases, 6.180 yellow cases, 9.270 red cases and 3,090 black cases. Overall triage accuracy was 89,63%. The overall errors were 2.671 (10.37%). Concerning the type of error, there were 1.415 cases under-triaged (5.5%) and 1.256 cases over- triaged (4.88%). Based on color-code, the highest rate of error was in green cases (3.48%), while black patients showed the highest accuracy rate (0.32%). Based on type, the most frequent error was under-triage of red patients, while the less frequent was over-triage of black patients.

The results of the final test performed by EMS personnel showed the accuracy rates of triage using new 5-color code-MCI triage systems of Regione Piemonte to be in range with data reported in the literature. A study limitation is the fact that the data analyzed are derived from online testing performed in no-time limited and no-stress conditions. Another potential limitation is the distance learning which doesn’t allow a discussion with the teacher or a request for clarification. For this reason, we would plan a future study defining the efficacy of the didactic methodology in comparison with face-to-face courses.