1. Department of Immunohematology and Blood TransfusionLeiden University Medical Center Leiden the Netherlands
2. University Hospitals Bristol NHS Foundation Trust and NHS Blood and Transplant Bristol Bristol United Kingdom
3. Medical Statistics Department of Biomedical Data SciencesLeiden University Medical Center Leiden the Netherlands
4. Oxford University Hospitals NHS Foundation Trust & Oxford BRC Hematology Theme Oxford Oxford United Kingdom
5. Department of HematologyRoyal Free Hospital London London United Kingdom
6. Department of HematologyHAGA Hospital The Hague the Netherlands
7. Department of PediatricsLeiden University Medical Center Leiden the Netherlands
8. Center for Clinical Transfusion ResearchSanquin‐LUMC Leiden the Netherlands