Request for further standardization issues for future studies in paediatric haemophilia patients – Rebuttal to “Including the life-time cumulative number of joint bleeds in the definition of primary prophylaxis” - Halimeh, Susan; Krümpel, Anne; Schobess, Rosemarie; Kurnik, Karin; Friedrichs, Frauke; Bidlingmaier, Christoph; Nowak-Göttl, Ulrike (Thrombosis and Haemostasis, 2008)