1. Center for Benign Haematology Thrombosis and Haemostasis Van Creveldkliniek University Medical Center Utrecht Utrecht University Utrecht the Netherlands
2. Center for Child Development Exercise and Physical Literacy University Medical Center Utrecht Utrecht University University Children's Hospital Utrecht the Netherlands
3. Netherlands Haemophilia Society (NVHP) Nijkerk the Netherlands
4. Department of Haematology Radboud University Medical Center Nijmegen the Netherlands
5. Haemophilia Treatment Center Nijmegen‐Eindhoven‐Maastricht Radboud University Medical Center Nijmegen the Netherlands
6. Department of Vascular Medicine Amsterdam Cardiovascular Sciences Amsterdam University Medical Centers University of Amsterdam Amsterdam the Netherlands
7. Emma Children's Hospital Amsterdam UMC University of Amsterdam Pediatric Hematology Amsterdam the Netherlands
8. Department of Clinical Epidemiology Leiden University Medical Center Leiden the Netherlands