As part of their work, emergency first responders, such as paramedics and emergency medical dispatchers are exposed daily to traumatic events. These traumatic events can have many impacts on mental health, such as acute stress disorder and post-traumatic stress disorder. Research has shown that intervening early after exposure to a traumatic event helps to identify people at risk and to prevent post-traumatic stress disorder. The Psychological First Aid approach originally developed for mass traumas, is an intervention advocated by international experts today following a traumatic event. However, this approach is still very little studied, especially when it is part of an organization of emergency first responders. It therefore still lacks scientific validity. The main objective of this research will be to assess whether the Psychological First Aid program provided by peer-support workers helps to reduce the initial distress caused by traumatic events and to foster short- and long-term adaptive functioning and coping.

In May 2018, Urgences-Santé (i.e., EMT corporation for the Montreal area) implemented PFA as a peer-support intervention for EMT affected by traumatic events in the course of their work. In collaboration with Urgences-Santé, this project aims to evaluate the feasibility of PFA as a post-traumatic peer-support intervention among EMT. Feasibility studies are used to determine whether an intervention should be recommended for efficacy testing when there are few previously published studies or existing data using a specific intervention technique. This catalyst project relies on participatory research principles. With Urgences-Santé stakeholders, three specific research objectives were elaborated in order to answer the question "Can PFA work for EMT?":

1. To assess the acceptability of PFA for EMT;
2. To assess the implementation of PFA in Urgences-Santé;
3. To test the limited-efficacy (i.e., efficacy within limitations such as small sample size and convenience sampling of PFA among Urgences-Santé trauma-exposed EMT).

Based on the few studies that assess different aspects of the feasibility of PFA in high-risk organizations, this project relies on three working hypotheses. First, we expect that PFA be acceptable among EMT. Second, we stipulate that few obstacles limited the implementation of PFA in Urgences-Santé given that this organization followed Forbes' implementation framework and favored a train-the-trainer approach. Third, we foresee that PFA will accelerate the recovery process of EMT, as measured by a greater decrease in PTSI, heart rate and absenteeism in the days following the traumatic event among those who received PFA compared to those who received the standard intervention (i.e., reference to employee aid program). If confirmed, these hypotheses will allow us to affirm that PFA can work as a post-traumatic intervention among EMT for the prevention of PTSI. Our results would therefore represent a catalyst towards a larger RCT that would answer the question "Does PFA work for EMT?" with an adequate sample size.

Inclusion Criteria:

• Actively working at Urgence-Santé organization as paramedics or emergency medical dispatchers
• Exposed to a traumatic event at work (after the baseline)

Exclusion Criteria:

- at high risk of suicidal behaviour