Development of a Cognitive Aid for First Medical Responders During Mass Casualty Incidents: A Delphi Consensus Study

No standardized cognitive aid (CA) exists to support the first medical responder during the initial organizational phase of a mass casualty incident (MCI). We aimed to develop such a tool through expert consensus using the Delphi method.A 2-round Delphi process was conducted with 20 expert prehospital physicians. Following a structured literature review, 46 items were submitted for evaluation using a 9-point Likert scale. Consensus criteria were defined a priori in accordance with HAS methodological guidelines. Retained items were ergonomically optimized using the Cognitive Aids in Medicine Assessment Tool (CMAT).All 20 experts participated in round 1 (100%); 18 completed round 2 (90%). After 2 rounds, 31 items were retained (acceptance rate 67%): 20 with strong agreement and 11 with relative agreement. The final CA is organized along the operational timeline of the first medical responder.This Delphi-based CA provides a structured, consensus-derived support tool for first medical responders during MCIs. Prospective studies in real or high-fidelity simulation settings are needed to evaluate its operational impact.