Factors Associated with the Application of Automated External Defibrillators to Out-of-Hospital Cardiac Arrest Patients in Japan - A Nationwide Cross-Sectional Study

OBJECTIVES: The objectives of this study were to evaluate factors associated with automated external defibrillator (AED) application to out-of-hospital cardiac arrest (OHCA) patients. METHODS: This retrospective cohort study used data from the All-Japan Utstein and Emergency Transport Registries for 2021. The application of AED was classified according to the bystander defibrillation field in the Utstein data. Cases where an AED was applied and the AED pads were attached were defined as "AED applied" and those with unknown AED application as "AED not applied." Multivariable logistic regression was used to estimate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for factors related to AED applied. RESULTS: = 105,436 [89.5%]). Factors associated with AED applied included daytime occurrence (AOR [95%CI], 1.14 [1.08-1.20] vs. nighttime), conventional cardiopulmonary resuscitation (CPR) (2.29 [2.09-2.50] vs. hands-only CPR), dispatcher assistance (2.02 [1.92-2.12]), and occurrence in a school (3.53 [2.58-4.82] vs. public place). Factors associated with AED not applied included age ≥65 years (0.92 [0.84-0.99] vs. 19-64 years), witnessed by family members (0.55 [0.48-0.64] vs. unwitnessed), no bystander CPR (0.28 [0.26-0.30] vs. hands-only CPR), and occurrences in a home (0.01 [0.01-0.01] vs. public place). CONCLUSIONS: The application of AED was associated with patient age, witness status, bystander CPR, and incident location. These findings should inform the placement of AEDs and educational strategies.