Centre for Evidence-Based Practice, Belgian Red Cross, Mechelen, Belgium. South Danish Transfusion Service & Tissue Center, Department of Clinical Immunology, Odense University Hospital, Odense, Denmark. Faculty of Medicine, University of Alberta, Edmonton, Canada. Transfusion and Transplantation Medicine, Alberta Precision Laboratories, Calgary, Alberta, Canada. Departments of Medicine, Laboratory Medicine and Pathobiology, Institute of Health Policy Management and Evaluation, University of Toronto, Mount Sinai Hospital, Toronto, Canada. Transfusion Medicine, NHS Blood and Transplant, Oxford, UK. Radcliffe Department of Medicine, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK. Department of Haematology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK. Department of Public Health and Primary Care, Leuven Institute for Healthcare Policy, KU Leuven, Leuven, Belgium. Blood Services, Belgian Red Cross, Mechelen, Belgium. Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium. Belgian Red Cross, Mechelen, Belgium. Division of Epidemiology and Biostatistics, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.