Public-access defibrillation and neurological outcomes in patients with out-of-hospital cardiac arrest in Japan: a population-based cohort study

Background: More than 80% of public-access defibrillation attempts do not result in sustained return of spontaneous circulation in patients who have had an out-of-hospital cardiac arrest (OHCA) and a shockable heart rhythm before arrival of emergency medical service (EMS) personnel. Neurological and survival outcomes in such patients have not been evaluated. We aimed to assess the neurological status and survival outcomes in such patients. Methods: This is a retropective analysis of a cohort study from a prospective, nationwide, population-based registry of 1 299 784 patients who had an OHCA event between Jan 1, 2005, and Dec 31, 2015 in Japan. The primary outcome was favourable neurological outcome (Cerebral Performance Category of 1 or 2) at 30 days after the OHCA and the secondary outcome was survival at 30 days following the OHCA. This study is registered with the University Hospital Medical Information Network Clinical Trials Registry, UMIN000009918. Findings: We identified 28 019 patients with bystander-witnessed OHCA and shockable heart rhythm who had received CPR from a bystander. Of these, 2242 (8·0%) patients did not achieve return of spontaneous circulation with CPR plus public-access defibrillation, and 25 087 (89·5%) patients did not achieve return of spontaneous circulation with CPR alone before EMS arrival. The proportion of patients with a favourable neurological outcome was significantly higher in those who received public-access defibrillation than those who did not (845 [37·7%] vs 5676 [22·6%]; adjusted odds ratio [OR] after propensity score-matching, 1·45 [95% CI 1·24–1·69], p<0·0001). The proportion of patients who survived at 30 days after the OHCA was also significantly higher in those who received public-access defibrillation than those who did not (987 [44·0%] vs 7976 [31·8%]; adjusted OR after propensity score-matching, 1·31 [95% CI 1·13–1·52], p<0·0001). Interpretation: Our findings support the benefits of public-access defibrillation and greater accessibility and availability of automated external defibrillators in the community. Funding: None.