Assessment of risk of bias and applicability of the single-lead ECG studies. (Desteghe et al., 2017(A): testing the AliveCor in the cardiology ward population; Desteghe et al., 2017 (B): testing the MyDiagnostick in the cardiology ward population; Desteghe et al., 2017 (C): testing the AliveCor in the geriatric ward population; Desteghe et al., 2017 (D): testing the MyDiagnostick in the geriatric ward population; Ford et al., 2022 (A): testing the Apple Watch 4; Ford et al., 2022 (B): testing the KardiaBand; Fu et al., 2021 (A): testing the device in supine position, Fu et al., 2021 (B): testing the device in upright position, Fu et al., 2021 (C): testing the device after individuals climbed to the 3rd floor; Santala et al., 2021 (1): published in October 2021, Santala et al., 2021 (2) (A): published in May 2021 and testing the device between the palms, Santala et al., 2021, (2) (B): published in May 2021 and testing the device in the chest; Abu-Alrub et al., 2022(A): testing the Apple Watch 5, Abu-Alrub et al., 2022 (B): testing the Samsung Galaxy Watch Active 3, Abu-Alrub et al., 2022 (C): testing the Withings Move ECG; Wegner et al., 2020 (A): testing the lead I; Wegner et al., 2020 (B): testing the novel parasternal lead).