Trauma‐exposed individuals are at risk of developing mental health problems, including posttraumatic stress disorder (PTSD). As an exposed individual's friend or family member may be the first person to provide posttrauma relief, informing and training laypeople in psychosocial first aid may benefit mental health outcomes of trauma‐exposed individuals. We aimed to (a) collect the best available evidence on communication as a first aid intervention in assisting individuals following traumatic events and (b) formulate practical recommendations. Systematic literature searches were conducted in three databases (March 2019). Following study selection, the extracted data were tabulated and synthesized narratively. The evidence was appraised according to the GRADE methodology and evaluated by a multidisciplinary expert panel to formulate recommendations for practice. Out of 1,724 articles, no experimental studies were identified, showing a complete lack of high‐quality controlled studies on the efficacy of communicative practices. However, when lower‐quality study designs were included, nine cross‐sectional studies constituted the best available evidence. The studies suggested that positive communication by family members, r = −.38, aOR = 0.26, β = −.22, p < .001–p < .05, and expressive coping by the victim, β = −.62, p < .001, were associated with PTSD diagnosis and/or symptom severity; however, the evidence was of very low certainty. The expert panel took the methodological limitations into account when formulating weak practical recommendations. Cross‐sectional studies currently provide the best possible evidence for developing guidelines on psychosocial first aid. High‐quality controlled studies are needed to establish casual associations and identify the most effective interventions.

BackgroundFirst aid training is a cost-effective way to improve public health, but the most effective methods to teach first aid are currently unclear. The aim of this research was to investigate the added value of simulated patients during first aid certification trainings.MethodsOccupational first aid trainings organized by the Belgian Red Cross between September 2018 and August 2019 were allocated to either training with a simulated patient or regular training, for the topics “stroke” and “burns.” Participants' knowledge and self-efficacy related to these topics were assessed at baseline, directly after training and after 1 year. First aid skills for “stroke” and “burns” and participant satisfaction were assessed after training. Knowledge and self-efficacy were measured via a questionnaire, and skills were assessed during a practical skills test. Data were analyzed using generalized linear mixed model analyses.ResultsA total of 1113 participants were enrolled, 403 in the simulated patient group and 710 in the control group. First aid knowledge and self-efficacy increased strongly immediately after training. These increases did not differ between groups, nor did the level of practical skills. The simulated patient group had a significantly increased retention in first aid knowledge after 1 year, compared with control, while retention in self-efficacy did not differ. Participant satisfaction with training was similar between groups.ConclusionsUsing simulated patients during occupational first aid trainings for laypeople did not improve outcomes immediately after training but did improve retention of first aid knowledge after 1 year. These results support the use of simulated patients during first aid training.