1. NHS Blood and Transplant/Oxford University Hospitals NHS Trust, John Radcliffe Hospital, and Radcliffe Department of Medicine, University of Oxford, Oxford, UK
2. Centre for Trauma Sciences, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
3. Department of Haematology, Churchill Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
4. NHS Blood and Transplant, Statistics and Clinical Studies, Bristol, UK
5. Trauma Audit and Research, Academic Health Science Centre, Institute of Population Health, University of Manchester, Salford Royal Hospitals NHS Foundation Trust, Salford, UK
6. University of Sheffield/University of Manchester/Salford Royal Hospitals NHS Foundation Trust, EMRiS Group, Health Services Research Section, School of Health and Related Research, University of Sheffield, Sheffield, UK