1. Clinical Trials Unit, NHS Blood and Transplant, John Radcliffe Hospital, Oxford, UK
2. Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
3. Wexham Park Hospital, Slough, UK
4. Horton General Hospital, Banbury, UK
5. North Bristol NHS Trust, Southmead Hospital, Bristol, UK
6. Oxford Institute of Nursing, Midwifery and Allied Health Research (OxINMAHR), Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK