*3.1. Population*

All EPs voluntarily registered to an Incident Command System course at a major hospital in Bangkok, Thailand. Participants who were present during the entire course session were included. Consequently, those who could not present or left the course for a few hours were excluded. Otherwise, there were no exclusion criteria, and all sta ff working with MID, including nurses could take part in the course.

#### *3.2. Course Design*

Two two-day courses with the same structure consisting of a short introduction and a scenario simulation exercise on the first day, followed by two more scenarios on day two. A round of discussion and comments for the whole course took place at the end of the course. Participants were divided into three groups of (1) a prehospital team (Operational), (2) emergency departments command group (Tactical), and (3) hospital command group (Strategical).

There was a rotation between di fferent groups, which enabled all participants to try di fferent positions to reach consensus in the whole group of participants to achieve similarities rather than di fferences. No instruction was given about participants' posts in each group, and they had to figure out what they need and how to use all competences, based on the given lectures and earlier knowledge in MIMMS. Three di fferent scenarios (1) fire in a tall building, (2) a terrorist attack and a bomb explosion, and (3) riots, including shooting, were presented to the groups during rotation (Appendix A). After each scenario, the participants in each group had to present their results. Each group received comments from supervisors and other participants. At the end of the presentations, and according to the 3LC model, the participants in each group had to gather again and discuss what they could do better if they had a new opportunity. Each group presented the results of this round, and other participants and supervisors could comment on their findings. Finally, each group gathered to discuss the necessary knowledge and functions and guidelines for each position to be taken home as the quality, which is needed for operational, tactical, and strategic levels. Besides, two supervisors followed each group and evaluated their performance based on MIMMS-CSCATT concept (see below) [18].

#### *3.3. Pre- and Post-Course Test*

The pre- and post-course tests were conducted to evaluate the gained knowledge in each participant [25]. The tests were designed using the learning objectives established for the course, i.e., crucial factors for successful managemen<sup>t</sup> of MID incorporated in CSCATTT (Command and control, Security, Communication, Assessment, Triage, Treatment, Transport), a well-known model used in MIMMS courses internationally [18]. Both tests consist of the same items. The test aimed for each participant's self-assessment in knowledge about the subjects of CSCATTT, displayed as a Likert scale, in which No knowledge was represented by 0%, while 100% was full knowledge. Participants were asked to mark the grade of their understanding in each topic on a five-level Likert Scale. A nonparametric test, Wilcoxon signed rank test, was chosen to compare the means.

## *3.4. Observational Evaluation*

All groups were observed based on a Participant Observation model with a focus on the leadership in all groups [26–28]. Among various signs of good leadership, the following points were mainly observed to evaluate the leadership: Communication and Decision-making ability, Accountability, Delegation, and Empowerment of others. Two observers collected and noted their observations, which were discussed after each scenario to reach a consensus. The observer registered if a commander was identified and appointed during the incident and if the appointed commander possessed the control. The observer did also register if the commander ensured successful medical management, i.e., built a team of multiple sta ff overcoming a potentially chaotic situation and if the team reached a subtactical, tactical, or operational level [18]. The data were recorded as Event Sampling, which allows focusing on one specific subject. All other types of behavior were ignored [26–28].

## *3.5. Observational Evaluation*

As part of 3LC simulation training, group discussions took place after each scenario. Besides confirming and discussing the results and improvement measures, these discussions also aimed to discuss the observational findings in each occasion. The process aimed to pair data collected by observation to the discussion and interviews to unearth individual motivations or behaviors that were not immediately obvious in a group setting [24–28].
