2.4 Data extraction:
Two authors (SSR, AMF, VDPG) independently performed data extraction from included studied, which was then cross-checked by the third author (AK) to reduce errors. From each included study, the following details were retrieved, the first author’s name, the origin country of the analysis, study design, number of COVID-19 patients, median age, gender (female sex proportion), patients with NOAF, data on patients with pre-existing atrial fibrillation if available, ICU admitted patients or patients with respiratory failure, and all-cause mortality. Criteria for severe disease was ICU admission or respiratory failure.