Department of Medicine, McMaster University, Hamilton, ON, Canada; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; McMaster Centre for Transfusion Research, McMaster University, Hamilton, ON, Canada. Centre for Innovation Canadian Blood Services, Hamilton, ON, Canada; Population Health Research Institute, Hamilton, ON, Canada. Meir Medical Centre Kfar Saba and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; SA Pathology Transfusion Service, Flinders Medical Centre and Flinders University, Adelaide, SA, Australia; Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA; Thrombosis & Atherosclerosis Research Institute, Hamilton, ON, Canada.