Characteristics of Out-of-hospital Cardiac Arrest from 2018 to 2021 across the World: Third Report from the International Liaison Committee on Resuscitation (ILCOR) Research and Registries Committee.

Background: The International Liaison Committee on Resuscitation (ILCOR) Research and Registries Committee previously reported 2015 data on systems of care and outcomes for out-of-hospital cardiac arrest (OHCA) from 16 registries and 2015 to 2017 data from 15 registries. To describe updated data on OHCA, we report the characteristics of OHCAs from 2018 through 2021.

Methods: We invited national and regional population-based OHCA registries to participate voluntarily and included emergency medical services-treated OHCAs. We collected descriptive summary data of core elements of the Utstein OHCA registry template from 2018 through 2021 at each registry.

Results: Thirteen national and five regional registries from North America, Europe, Asia, and Oceania were included in this report. The provision of bystander cardiopulmonary resuscitation ranged from 9.6% to 83.8% (median 61.7%) and shocks by public access automated external defibrillator from 0.5% to 11.7% (median 2.3%) in 2021. Survival to hospital discharge or 30-day survival for bystander-witnessed shockable OHCA ranged from 19.9% to 44.4% (median 28.3%), and neurologically favourable outcome ranged from 9.5% to 35.1% (median 22.0%) in 2021. The majority of registries showed that survival and favourable neurological outcomes were lower in the 2020-2021 COVID-19 pandemic period compared with those in 2018-2019.

Conclusion: This report from ILCOR presents summary data for OHCA systems of care and outcomes from 2018 through 2021 from 18 national and regional OHCA registries worldwide. We observed a persisting wide variability in OHCA characteristics and outcomes across registries and the potential impact of the COVID-19 pandemic within registries.