Reducing cognitive load in dispatcher-assisted CPR: a simulation-based educational study among non-medical university students

BACKGROUND: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) is critical for improving outcomes after out-of-hospital cardiac arrest, yet untrained callers often experience high cognitive load that impedes early recognition and action. Communication strategies grounded in instructional design may reduce this burden. We evaluated whether a simplified dispatcher script developed using Cognitive Load Theory (CLT) and the ADDIE framework improves DA-CPR performance in a simulated setting. METHODS: We conducted a simulation-based randomized study among undergraduate non-medical students in Thailand. Participants without prior CPR training were randomly assigned to receive either the standard NIEMS 2013 dispatcher script or a CLT-ADDIE simplified script during a simulated cardiac arrest scenario. Participants were blinded to allocation; dispatchers received concealed assignment prior to simulation, and outcome assessors were blinded. Primary outcomes were time to cardiac arrest recognition and time to first chest compression. Secondary outcomes included CPR quality and perceived cognitive load measured by the 9-point Paas scale. RESULTS: Forty-two participants completed the simulation. Cardiac arrest recognition within 60 s was more frequent in the simplified group than in the standard group (90.5% vs. 47.6%, p = 0.034). Median recognition time was shorter with the simplified script (52 [45-60] vs. 74 [60-90] seconds), and perceived cognitive load was lower (median 4 [IQR 3-5] vs. 6 [IQR 5-7], p = 0.018). Qualitative observations suggested clearer task sequencing and reduced confusion. CONCLUSION: A CLT-ADDIE-based simplified dispatcher script improved early recognition of cardiac arrest and reduced cognitive load in a simulated DA-CPR context. Instructional design-informed dispatcher communication may enhance bystander performance during time-critical emergencies.