1. NHS Blood and Transplant; Haematology/Transfusion Medicine; Level 2, John Radcliffe Hospital Headington Oxford UK OX3 9BQ
2. Systematic Review Initiative, NHS Blood and Transplant; Oxford UK
3. University of Oxford; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS); Botnar Research Centre, Windmill Road Oxford Oxfordshire UK OX3 7LD
4. University of Oxford; Centre for Statistics in Medicine; Botnar Research Centre Windmill Road Oxford UK OX3 7LD
5. NHS Blood and Transplant; Systematic Review Initiative; John Radcliffe Hospital Oxford UK OX3 9BQ
6. American University of Beirut Medical Center; Department of Pediatrics and Adolescent Medicine; Beirut Lebanon