1. Centre for Haematology, Faculty of Medicine, Imperial College London, London, United Kingdom;
2. Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands;
3. Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands;
4. Utrecht Stroke Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands; and
5. Department of Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, The Netherlands