[1] Manchester Royal Infirm, Dept Clin Haematol, Manchester M13 9WL, Lancs, England
[2] Manchester Royal Infirm, Dept Haematol, Manchester M13 9WL, Lancs, England
[3] Yorkhill NHS Trust, Royal Hosp Sick Children, Dept Haematol, Glasgow, Lanark, Scotland
[4] Univ Wales Hosp, Arthur Bloom Haemophilia Ctr, Cardiff CF4 4XW, S Glam, Wales
[5] Churchill Hosp, Oxford Haemophilia Ctr, Oxford OX3 7LJ, England
[6] Churchill Hosp, Thombosis Unit, Oxford OX3 7LJ, England
[7] Royal Hallamshire Hosp, Sheffield Haemophilia & Thombosis Ctr, Dept Coagulat, Sheffield S10 2JF, S Yorkshire, England
[8] Great Ormond St Hosp Sick Children, Haemophilia Comprehens Care Ctr, Bristol, Avon, England
[9] Bradford Royal Infirm, Haemophilia Ctr, Bradford BD9 6RJ, W Yorkshire, England
[10] Bristol Haematol & Oncol Med Sci, Bristol Haemophilia Ctr, Bristol, Avon, England
[11] Addenbrookes Hosp, Dept Haematol, Cambridge CB2 2QB, England
[12] Univ Birmingham, Inst Biomed Res, Div Med Sci, Ctr Cardiovasc Sci, Birmingham B15 2TT, W Midlands, England
[13] Univ Hosp Birmingham, Dept Haematol, Birmingham, W Midlands, England
[14] Birmigham Childrens Hosp, Dept Clin & Lab Haematol, Birmingham, W Midlands, England