Timing of Public-Access Defibrillation for Patients With Out-of-Hospital Cardiac Arrest: A Nationwide Cohort Study Using Time-Dependent Propensity Score Sequential Matching Approach

Why clinicians should know about it

• Picked for Emergency Medicine (paper of the day, 1 August 2026).

Abstract

BACKGROUND: Earlier defibrillation is a key factor in improving survival in patients with out-of-hospital cardiac arrest due to ventricular fibrillation. Although the benefit of public-access defibrillation (PAD) has been reported, its effectiveness has rarely been evaluated considering intervention time. We assessed whether the effect of PAD varies depending on the timing of defibrillation. METHODS: Using a nationwide, prospective, population-based out-of-hospital cardiac arrest registry in Japan between 2022 and 2023, we included consecutive bystander-witnessed ventricular fibrillation with resuscitation attempts in public locations. Patients with out-of-hospital cardiac arrest who received PAD before emergency medical services arrival were sequentially matched with patients at risk of receiving PAD on a minute-by-minute basis using time-dependent propensity scores to address resuscitation time bias. The primary outcome was 1-month survival with favorable neurological outcome, defined as a cerebral performance category scale of 1 or 2. RESULTS: After sequential matching, 1664 matched pairs were identified. The corrected risk ratio for 1-month survival with favorable neurological outcome in the PAD group than in the non-PAD group was 1.46 (95% CI, 1.34-1.59). The effect sizes by PAD timing were 1.33 (95% CI, 1.19-1.48) for 0 to 4 minutes, 1.49 (95% CI, 1.30-1.70) for 5 to 9 minutes, 1.55 (95% CI, 1.12-2.14) for 10 to 14 minutes, 2.46 (95% CI, 0.83-7.30) for 15 to 19 minutes, and 1.19 (95% CI, 0.29-4.85) after 20 minutes. CONCLUSION: In Japan, among patients with bystander-witnessed ventricular fibrillation in public locations, PAD before emergency medical services arrival was significantly associated with favorable neurological outcome, showing a directionally consistent association with improved outcomes regardless of time to emergency medical services arrival.

Abstract as published, via PubMed.