[1] St Thomas Hosp, Ctr Haemostasis & Thrombosis, London SE1 7EH, England
[2] Basingstoke & N Hampshire NHS Fdn Trust, Haemophilia Haemostasis & Thrombosis Ctr, Basingstoke, Hants, England
[3] Royal Free Hosp NHS Trust, Dormandy Haemophilia Ctr, London, England
[4] Univ Hosp Birmingham, Haemophilia Unit, Birmingham, W Midlands, England
[5] Royal Free Hosp NHS Trust, Thrombosis Unit, London, England