Completion of the First Phase of Registration: Baseline Characteristics and Epidemiology of Hemophilia in Korea from the Korean Bleeding Disorder Registry (KBDR)
Authors: Han Jung Woo , Baek Hee Jo , Park Young Shil , Park Sangkyu , Yoo Ki Young , Choi Eun Jin , KIM JI Yoon , Hahn Seung Min , Ahn Won Kee , Lee Haewon , Kwon Seung Yeon , Lyu Chuhl Joo , Kim Soon Ki 
Published: December 2024

Background
Hemophilia is a rare bleeding disorder that requires thorough investigation to understand its epidemiology, natural history, and the medical environment in which patients receive care. A patient registry is pivotal for such investigations. We established the first comprehensive hemophilia registry in Korea and reported preliminary baseline characteristics in 2022, with a total of 625 registered patients. We have now completed the first stage of the registry and present the final results of this initial phase.
Methods
We developed the registry platform using iCReaT (Internet-based Clinical Research and Trial Management System) operated by the National Institute of Health in Korea. The registry is designed as a combined retrospective and prospective study for bleeding disorders. In the first stage, we collected retrospective data to provide an overview of the clinical status and epidemiology of bleeding disorders in Korea. Seven major institutions for hemophilia care in Korea participated in the establishment of the registry, which is open for participation from other centers across Korea. Data collection was conducted under the approval of the Institutional Review Board at each participating institution.
Results
As of July 2024, a total of 2922 patients were registered, capturing a nearly complete picture of hemophilia in Korea. The current age of this cohort is 38.2 ± 18.9 years (mean) and 36.4 years (median) [IQR, 24.2; 51.6]. Geographic distribution includes Seoul (646, 22.1%), Gyunggi (735, 25.2%), Gwangju (146, 5.0%), Chonnam (124, 4.2%), Incheon (170, 5.8%), Ulsan (50, 1.7%), among others. Hemophilia types were distributed as follows: hemophilia A (2120, 72.6%), hemophilia B (536, 18.3%), factor 7 deficiency (60, 2.1%), hemophilia C (41, 1.4%), factor 1 deficiency (7, 0.2%), and others. Severe hemophilia was observed in 66.0% (1399) of hemophilia A cases and 48.3% (259) of hemophilia B cases. Prophylaxis was performed in 74.0% (1568) of hemophilia A and 68.5% (367) of hemophilia B patients. A total of 1242 orthopedic procedures were performed in 1108 patients, with the most frequent sites of operation being the right knee (241) and right ankle (196) in hemophilia A, and the right knee (32) and right ankle (27) in hemophilia B. Joint replacement surgery was conducted 334 times in hemophilia A and 42 times in hemophilia B. Chronic viral infections included hepatitis C (393, 18.5% in hemophilia A; 68, 12.7% in hemophilia B) and HIV (7, 0.3% in hemophilia A; 18, 3.4% in hemophilia B).
Conclusion
We have completed the first phase of registration for the hemophilia registry in Korea. In this comprehensive analysis, 2922 patients were registered, representing a 4.5-fold increase since 2022. We described the baseline characteristics of the hemophilia registry and are now proceeding to the second phase, which will involve prospective observation. This registry data significantly enhances our understanding of hemophilia in Korea and serves as a cornerstone for future clinical studies aimed at improving the survival and quality of life of patients with hemophilia.