[1] Leicester Royal Infirm, Leicester Haemophilia Ctr, Haemostasis & Thrombosis Unit, Level 2,Osborne Bldg,Infirm Sq, Leicester LE1 5WW, Leics, England
[2] Manchester Royal Infirm, Haematol Dept, Manchester, Lancs, England
[3] St Thomas Hosp, Evelina Childrens Hosp, Haemophilia Dept, London, England
[4] Birmingham Childrens Hosp, Haemophilia Comprehens Care Ctr, Birmingham, W Midlands, England
[5] Royal Free Hosp, Katharine Dormandy Haemophilia Ctr, London, England