Real-World Data on Patients With Acquired Haemophilia A in Japan Undergoing Rehabilitation or With Low Activities of Daily Living Scores: The ORIHIME II Study

Introduction: Acquired haemophilia A (AHA) is characterized by the development of autoantibodies against factor VIII, reducing its activity and potentially resulting in bleeding.

Aim: To assess the characteristics of people with AHA undergoing rehabilitation and/or with low activities of daily living (ADL) scores, thereby characterizing unmet needs in the management of AHA and informing treatment optimization.

Methods: ORIHIME II, the largest epidemiological and treatment survey of AHA in Japan, is a descriptive, retrospective, observational study conducted using health claims data from April 2008 to October 2021. The primary outcome measures were rehabilitation practice and ADL scores on hospital admission and discharge; use of haemostatic agents and immunosuppressive therapy were also assessed.

Results: Overall, 427 patients in Japan were eligible for the study. Median (Q1-Q3) age was 78.0 (70.0-84.0) years; 264 patients (61.8%) were male. Median (Q1-Q3) time to start rehabilitation was 9 (4-21) and 14 (6-31) days for those with an admission ADL score of <85 and ≥85, respectively. Of the 427 patients, 249 underwent rehabilitation. The most common rehabilitation type was for disuse syndrome; haemostatic agents were more commonly used in patients undergoing earlier rehabilitation.

Conclusion: The physical condition of the patient at hospitalization was associated with rehabilitation practice and the ability of the patient to perform day-to-day activities independently. Treatment strategies should be optimized to allow initiation of rehabilitation as early as possible in the course of AHA.