Traumatic hemorrhage is one of the leading causes of preventable death worldwide, and early hemorrhage control is critical for survival. In many emergency situations, the first individuals present are medical laypeople rather than professional responders. These immediate responders face extreme time pressure, uncertainty, and stress, yet are increasingly expected to initiate life-saving interventions such as hemorrhage control. Despite widespread implementation of civilian hemorrhage control initiatives, including the Stop the Bleed (STB) campaign, limited empirical knowledge exists regarding how laypeople perceive traumatic injuries, interpret severity, and perform hemorrhage control under realistic conditions. Training programs have largely been informed by clinical and military perspectives, with comparatively little grounding in cognitive science or human factors.

This thesis examines the cognitive, perceptual, and affective mechanisms underlying laypeople’s responses to life-threatening bleeding. Drawing on theories from cognitive science and human factors, most notably Brunswik’s lens model, naïve theories, and stress theory, the thesis conceptualizes medical emergencies as epistemic events shaped by uncertainty, probabilistic cues, and human sensemaking. From this perspective, recognizing and responding to hemorrhage is not solely a matter of technical skill acquisition, but of judgment under uncertainty, cue interpretation, and performance under stress.

The thesis consists of six papers. Five papers employing experimental, simulation-based methods, and one literature review. The included studies investigate how factors such as stress, exposure to blood, and visual characteristics of injuries influence laypeople’s ability to recognize hemorrhage, estimate blood loss, prioritize victims, and perform bleeding control interventions. Several studies directly assess performance rather than relying on surrogate outcomes such as confidence or intention, thereby addressing a key limitation in existing bleeding control research.

Across the included papers, the results demonstrate that laypeople’s hemorrhage control performance is systematically affected by cognitive and environmental constraints. Stress and salient trauma cues can impair both perceptual judgment and motor performance, while mismatches between perceived severity and actual injury severity highlight limitations in current training approaches. The findings suggest that conventional training models may insufficiently account for how laypeople attend to, interpret, and act upon probabilistic cues in emergency contexts.

By integrating empirical findings with theory-informed analysis, this thesis contributes to a more cognitively grounded understanding of layperson emergency response. The work advances knowledge on how hemorrhage control training can be better aligned with human perceptual and decision-making processes, and offers implications for the design of more effective, realistic, and transferable training for the general public. Ultimately, this research aims to support training practices that enhance early intervention capacity and societal resilience in medical emergencies.

Background:

Uncontrolled bleeding is a leading cause of preventable death following trauma, often occurring before professional medical care can be delivered. Training laypersons in basic hemorrhage control has therefore emerged as an important strategy to improve survival in mass casualty and everyday trauma situations. The “Stoppa blödningen” (Stop the Bleed) concept was developed in Sweden to enhance public preparedness and strengthen societal resilience through education in bleeding control. 

Objective:

This report aimed to evaluate the implementation of Stoppa blödningen training activities conducted in Sweden during 2024 and to provide a strategic foundation for future national dissemination and development of the educational concept.

Methods:The study combined evaluation of conducted training programs with a broader strategic analysis. Training outcomes were assessed through participant surveys and feedback from instructor and instructor-trainer courses. Additionally, literature reviews, international comparisons, and contextual analyses of trauma epidemiology and first aid education were integrated to inform recommendations for large-scale implementation.

Results:

A total of 23 instructor trainers and 23 instructors from multiple voluntary organizations were trained, generating a substantial capacity for further dissemination. Estimates suggest that this train-the-trainer model could enable education of over 20,000 laypersons annually. Participants reported high satisfaction with course design, particularly the emphasis on practical skills and interactive learning. However, challenges included time constraints, extensive preparatory materials, and administrative burden. The findings highlight the effectiveness of structured, multi-level training programs and demonstrate strong participant motivation linked to the life-saving purpose of hemorrhage control. Evidence from the literature confirms that layperson training improves knowledge, skills, confidence, and willingness to act in emergency situations.

Introduction:

The Covid-19 pandemic strained most of the world’s health care organizations to, and sometimes beyond, their limits. To anticipate, coordinate, mobilize, and prioritize hospital resources, Sweden’s health care regions established regional medical command and control teams according to the medical major incident structure. This command structure was initially developed based on an all-hazards approach focused primarily on sudden mass casualty incidents with a relatively short time frame. Covid-19 management was active for several months with a most intense operations period during the spring of 2020. This study aimed at identifying competence needs by employing a co-creative approach with members of the staff involved in the pandemic management.

Method:

Data was collected and analyzed using a modified Delphi consensus method. The respondents were subject matter experts serving in the regional medical command and control teams during the COVID-19 pandemic. One workshop was held to gather opinions, which were included as statements in a consensus survey and answered by the participants after the first workshop. A second workshop was held to discuss statements that did not reach initial consensus in the survey and establish final consensus.

Results:

The consensus agreed statements were sorted into five themes, which constituted the collective agreement of medical command and control core abilities. The five core competence themes were: Situation report, Team organization, Co-operation, Competence management, and Analysis. The consensus agreed statements highlighted competencies needed for creating situation reports, organizing medical command and control teams, effective cross-organization co-operation, decision-making, and medical intelligence analysis.

Conclusion:

The core competencies of medical command and control identified in the present study can be used to further affirm current learning objectives and to formulate future learning objectives for education and exercises. The evaluation approach could potentially be used as a post-incident review to fine-tune an organization’s training plan.

This paper presents an ethnographic study consisting of non-participatory observations of a Swedish regional medical command and control team during their crisis response to the COVID-19 pandemic. The field-notes from the observations were analyzed using a deductive content analysis with categories representing teamwork processes. The content analysis showed that the studied regional medical command and control team was engaged in all but one of the predefined teamwork processes. Furthermore, the content analysis also added to the understanding of the regional medical command and control teamÂ’s work procedures by emphasizing how the team was engaged in the different processes. Lastly, the content analysis also made it possible to identify potential developmental needs of the studied regional medical command and control team.

Objective The purpose of this study was to compare laypeoples and professional first responders ability to perform tourniquet application and cardiopulmonary resuscitation (CPR) during calm and stressful circumstances. Background Life-threatening bleeding is a major cause of death that could be prevented by fast and appropriate first aid interventions. Therefore, laypeople are now being trained in bleeding control skills, transforming them from bystanders to immediate responders. However, critics have questioned whether laypeople are able to perform during more stressful conditions. Method Twenty-four laypersons and 31 professional first responders were tested in two conditions: a calm classroom scenario and a stressful scenario consisting of paintball fire and physical exertion. Stress and workload were assessed along with task performance. Results The experimental manipulation was successful in terms of eliciting stress reactions. Tourniquet application performance did not decline in the stressful condition, but some aspects of CPR performance did for both groups. First responders experienced higher task engagement and lower distress, worry and workload than the laypeople in both the calm and stressful conditions. Conclusion Stress did not affect first responders and laypeople differently in terms of performance effects. Stress should therefore not be considered a major obstacle for teaching bleeding control skills to laypeople. Application Tourniquet application can be taught to laypeople in a short amount of time, and they can perform this skill during stress in controlled settings. Concerns about laypeoples ability to perform under stress should not exclude bleeding control skills from first aid courses for civilian laypeople.