First and Second Waves of Coronavirus Disease 2019 in Madrid, Spain: Clinical Characteristics and Hematological Risk Factors Associated With Critical/Fatal Illness oleh Irene Mollinedo-Gajate, PhD, Felipe Villar-Álvarez, MD, PhD, María de los Ángeles Zambrano-Chacón, MD, Laura Núñez-García, MD, Laura de la Dueña-Muñoz, MD, Carlos López-Chang, MD, Miguel Górgolas, MD, PhD, Alfonso Cabello, MD, PhD, Olga Sánchez-Pernaute, MD, PhD, Fredeswinda Romero-Bueno, MD, PhD, Álvaro Aceña, MD, PhD, Nicolás González-Mangado, MD, PhD, Germán Peces-Barba, MD, PhD, Faustino Mollinedo, PhD