Impact of Bystander Interventions in Out-of-Hospital Cardiac Arrest

Study Questions:

What is the impact of bystander intervention on the outcome of victims of out-of-hospital cardiac arrest (OHCA)?


Japanese patients who experienced a witnessed OHCA of cardiac origin between 2005 and 2012 were subjects of the study. The logistic regression model included factors such as defibrillation, chest compression, as well as other clinical and demographic factors. The primary outcome was neurologically-intact survival.


Among 925,288 patients with OHCA during the study period, 167,912 patients met the above criteria. The rates of bystander chest compression increased from 39% to 51%, bystander-only defibrillation from 0.1% to 2.3%, and bystander defibrillation combined with emergency medical service (EMS) defibrillation increased from 0.1% to 1.4%. During the study period, the number of patients who survived and were neurologically intact increased from 587 to 1,710. Bystander chest compression was associated with an improvement in neurologically-intact survival (8.4% vs. 4.1%; odds ratio [OR], 1.5; 95% confidence interval [CI], 1.4-1.6). Bystander-only defibrillation (as compared with EMS-only defibrillation) was associated with increased neurologically-intact survival (OR, 2.2; 95% CI, 1.9-2.6). Lack of defibrillation was associated with lower survival (OR, 0.43; 95% CI, 0.39-0.48).


In a Japanese population, the rate of bystander interventions increased over the study period and was associated with an improved neurologically-intact survival among victims of OHCA.


Despite incremental improvements, neurologically-intact survival following an OHCA remains very low. These data support educating the population at large (i.e., would be lay rescuers, in the benefits of chest compressions). They also support placement of automated external defibrillators at high-risk areas (e.g., casinos, sports venues) and training employees at such facilities in the appropriate use of these devices.

Clinical Topics: Arrhythmias and Clinical EP, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Arrhythmias, Cardiac, Cardiopulmonary Resuscitation, Defibrillators, Electric Countershock, Heart Arrest, Out-of-Hospital Cardiac Arrest, Survival

< Back to Listings