Departments of Medicine, Pathology and Molecular Medicine, and Clinical Epidemiology and Biostatistics and McMaster Centre for Transfusion Research, McMaster University; Canadian Blood Services; Population Health Research Institute; Thrombosis and Atherosclerosis Research Institute, Hamilton, ON; Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada; SA Pathology Transfusion Service, Flinders Medical Centre and Flinders University, Adelaide, SA, Australia; Departments of General Anesthesiology and Outcomes Research, Anesthesiology Institute, and the Robert J. Tomsich Pathology and Laboratory Medicine Institute and the Department of Laboratory Medicine, Cleveland Clinic, Cleveland; Meir Medical Center Kfar Saba and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.