Impact of the COVID-19 pandemic on favourable neurological outcome after EMS-witnessed out-of-hospital cardiac arrest: a prospective nationwide observational study.

Abstract

To evaluate the impact of the COVID-19 pandemic on favourable neurological outcome after out-of-cardiac arrest (OHCA) witnessed by emergency medical services (EMS) personnels in Japan. We conducted an interrupted time series analysis (ITSA) using a prospective, nationwide, population-based registry in Japan to assess 30-day favourable neurological outcome (Cerebral Performance Category 1 or 2), prehospital return of spontaneous circulation (ROSC), and 30-day survival among adult patients with EMS-witnessed OHCA during the pre-pandemic (January 2016-March 2020) and pandemic (April 2020-December 2021) periods. Subgroup analyses were performed by stratifying regions based on state of emergency declaration status. A controlled ITSA was conducted to compare outcome trends between areas with and without significant COVID-19 spread. In total, 58,315 adult patients with EMS-witnessed OHCA were identified. Favourable neurological outcome significantly declined during the pandemic (relative risk [RR], 0.80; 95 % CI, 0.71-0.91; p < 0.001). Prehospital ROSC and 30-day survival also decreased significantly (p < 0.05). In subgroup analyses, favourable neurological outcome declined in areas affected by COVID-19 spread (p < 0.001), while no significant change was observed in unaffected areas (p = 0.243). The controlled ITSA revealed a significantly greater decline in favourable neurological outcome in areas with COVID-19 spread compared with unaffected areas (RR, 0.77; 95 % CI, 0.60-0.98; p = 0.035). Favourable neurological outcomes among patients with EMS-witnessed OHCA in Japan were lower during the COVID-19 pandemic, particularly in regions affected by COVID-19 spread.