Impact of the COVID-19 pandemic on prehospital characteristics and outcomes of out-of-hospital cardiac arrest among the elderly in Japan: A nationwide study.

Aim: To assess the impact of the 2020 coronavirus disease (COVID-19) pandemic on the prehospital characteristics and outcomes of out-of-hospital cardiac arrest (OHCA) in the elderly.

Methods: In this population-based nationwide observational study in Japan, 563,100 emergency medical service-unwitnessed OHCAs in elderly (≥65 years) patients involving any prehospital resuscitation efforts were analysed (144,756, 140,741, 140,610, and 136,993 cases in 2020, 2019, 2018, and 2017, respectively). The epidemiology, characteristics, and outcomes associated with OHCAs in elderly patients were compared between 3 years pre-pandemic (2017-2019) and the pandemic year (2020). The primary outcome was neurologically favourable one-month survival. The secondary outcomes were the rate of bystander cardiopulmonary resuscitation (CPR), defibrillation by a bystander, dispatcher-assisted (DA)-CPR attempts, and one-month survival.

Results: During the pandemic year, the rates of neurologically favourable 1-month survival (crude odds ratio, 95% confidence interval: 1.19, 1.14-1.25), bystander CPR (1.04, 1.03-1.06), and DA-CPR attempts (1.10, 1.08-1.11) increased, whereas the incidence of public access defibrillation (0.88, 0.83-0.93) decreased. Subgroup analyses based on interaction tests showed that the increased rate of neurologically favourable survival during the pandemic year was enhanced in OHCA at care facilities (1.51, 1.36-1.68) and diminished or abolished on state-of-emergency days (0.90, 0.74-1.09), in the mainly affected prefectures (1.08, 1.01-1.15), and in cases with shockable initial rhythms (1.03, 0.96-1.12).

Conclusions: The COVID-19 pandemic increased the bystander CPR rate in association with enhanced DA-CPR attempts and improved the outcomes of elderly patients with OHCAs.