To analyse monthly changes in public access defibrillation (PAD) incidence and outcomes of out-of-hospital cardiac arrest (OHCA) during the 2020–2021 COVID-19 pandemic compared with those during the 2016–2019 prepandemic period with consideration of pandemic-related movement restriction.

Retrospective cohort study.

An extended database was created by combining and reconciling the nationwide Utstein-style OHCA and the emergency medical service (EMS) transportation databases in Japan.

We analysed 226 182 EMS-witnessed, non-newborn and out-of-home OHCA cases in Japan.

The primary outcomes were the PAD incidence and neurologically favourable 1-month survival rate. The secondary outcomes were bystander cardiopulmonary resuscitation (CPR) provision and dispatcher-assisted CPR attempts.

The proportion of out-of-home OHCA cases slightly decreased during the pandemic (from 33.7% to 31.9%). Although the pandemic was associated with a decreased PAD incidence, 2-year trend analyses by an interaction test showed that the PAD incidence was lower during the first nationwide declaration of a state of emergency (p

Prolonged and repeated movement restrictions during the COVID-19 pandemic worsened the OHCA outcomes concurrently with disturbed BLS actions, including the reduced PAD incidence in out-of-home settings. Maintaining BLS training, re-arranging automated external defibrillator placement and establishing a local alert system for recruiting well-trained citizens to the scene are essential.