Department of Medicine McMaster University, Hamilton, Ontario, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada; McMaster Centre for Transfusion Research, McMaster University, Hamilton, Ontario, Canada; Canadian Blood Services, Hamilton, Ontario, Canada; Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada; Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada; Population Health Research Institute, Hamilton, Ontario, Canada; Meir Medical Centre, Tel Aviv, Israel; Department of Outcomes Research, Cleveland Clinic, Cleveland, Ohio, USA; Flinders University and Flinders Medical Centre, Adelaide, South Australia; Thrombosis & Atherosclerosis Research Institute, Hamilton, Ontario, Canada.