Replication Study of “Visual Fixation on the Thorax Predicts Bystander Breathing Detection in Simulated Out-of-Hospital Cardiac Arrest”

Background: Early cardiopulmonary resuscitation (CPR) by lay responders is associated with improved survival from Out-of-Hospital Cardiac Arrest (OHCA). Recognition of OHCA, i.e., a victim who is unresponsive and not breathing, is essential to begin CPR as soon as possible. In 2022, we published a simulation study (Study 1; n = 96)which found that instructing lay responders to look at chest movement enables them to detect breathing. To expand the evidence and available data on this topic, we attempted a replication (Study 2; n= 73).Methods: Participants equipped with an eye tracker entered a room where a manikin, randomly set as breathing or unbreathing, lying on the floor. After the first simulation (pre-allocation), participants were randomly allocated to a video debriefing intervention with(experimental group) or without (control group) their recorded gaze overlay, in which they reviewed their thorax examination behavior. After debriefing, the simulation was repeated (post-allocation). The main outcome was success in detecting breathing.Results: Study 2 was underpowered and failed to support the findings of Study 1. Pooling together the results of the two studies (n = 170) supports the findings of Study 1: Success rate at post-allocation did not differ between the experimental (83%) and the control group (80%), but it significantly increased from pre-allocation (65%) to post-allocation (81%; χ2 = 10.88,p