1. Department of Paediatric Haematology; Erasmus MC - Sophia Children's Hospital; Rotterdam The Netherlands
2. Department of Public Health; Erasmus MC, University Medical Centre Rotterdam; Rotterdam The Netherlands
3. Department of Paediatric Haematology; Academic Medical Centre Amsterdam; Amsterdam The Netherlands
4. Department of Paediatric Haematology; University Medical Centre Groningen; Groningen The Netherlands
5. Department of Haematology; Erasmus MC, University Medical Centre Rotterdam; Rotterdam The Netherlands
6. Department of General Paediatrics; Erasmus MC - Sophia Children's Hospital; Rotterdam The Netherlands