ORIHIME study: real-world treatment patterns and clinical outcomes of 338 patients with acquired hemophilia A from a Japanese administrative database

BACKGROUND: Acquired hemophilia A (AHA) is a rare disorder, and clinical practices for treating AHA have not been fully clarified in Japan. OBJECTIVES: This study aims to investigate the epidemiology of AHA and real-world treatment practices in Japan. PATIENTS/METHODS: This observational study was based on a health administrative database of hospitalized patients diagnosed with AHA who were treated with immunosuppressants. RESULTS: The study included 214 males and 124 females (mean age 75.7 years). The most frequently used bypassing agent was recombinant activated factor VII. The predominant choice of immunosuppressant for first-line treatment was steroid monotherapy. Median days from the index date to the start of rehabilitation was 65.0 for cardiovascular, 35.5 for respiratory and 23.0 for locomotor. The proportion of patients with an activities of daily living (ADL) score < 70 points was high at both first admission and final discharge (47.4% and 38.8%). The percentage of deaths during hospitalization was 18.6%. CONCLUSIONS: This study clarified the treatment patterns and clinical outcomes of AHA in a large population in Japan. This was the first study showing ADL score distribution and time to rehabilitation. Further investigation is needed to develop better clinical practices for treatment of AHA. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12185-022-03467-w.