Correction: Is the heart rate variability monitoring using the analgesia nociception index a predictor of illness severity and mortality in critically ill patients with COVID-19? A pilot study. - Aragón-Benedí C; Oliver-Forniés P; Galluccio F; Altinpulluk EY; Ergonenc T; El Sayed Allam A; Salazar C; Fajardo-Pérez M (PloS one, 2021)