1. Department of Pediatrics Kyung Hee University Hospital at Gangdong Seoul South Korea
2. Korea Hemophilia Foundation Gwangju Clinic Gwang‐Ju South Korea
3. Korea Hemophilia Foundation Busan Clinic Busan South Korea
4. Department of Pediatrics Inha University Hospital Incheon South Korea
5. Department of Pediatrics Ulsan University Hospital Ulsan South Korea
6. Department of Pediatrics Kyungpook National University Hospital Daegu South Korea
7. Department of Pediatric Hematology and Oncology Kyungpook National University Chilgok Hospital Daegu South Korea
8. Department of Pediatrics Chonnam National University Hwasun HospitalChonnam National University Medical School Gwangju South Korea
9. Medical Department Pfizer Pharmaceuticals Korea Ltd Seoul South Korea
10. Department of Biostatistics and Computing Yonsei University Seoul South Korea
11. Korea Hemophilia Foundation Clinic (KHF Clinic Seoul South Korea