1. Haematology/Transfusion Medicine; NHS Blood and Transplant; Oxford UK
2. Haematology; Wolfson Institute of Preventive Medicine; London UK
3. Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS); University of Oxford; Oxford UK
4. Centre for Statistics in Medicine; University of Oxford; Oxford UK
5. Department of Hematology; St Jude Children's Research Hospital; Memphis Tennessee 38105 USA