Awareness of Acquired Hemophilia A among Physicians in Japan: A Web-based Survey.

Introduction: Acquired hemophilia A (AHA) is a rare, life-threatening bleeding disorder caused by the development of autoantibodies against coagulation factor VIII. AHA represents a diagnostic challenge, particularly for non-hematologist physicians who may initially encounter these patients. This study aimed to evaluate the level of AHA awareness among non-hematologist physicians across various medical departments in Japan. Methods: This was a prospective, cross-sectional, observational, web-based survey of non-hematologist physicians, conducted over a period of 2 weeks (April 1-12, 2024) in Japan. The primary endpoint was the participants' level of AHA awareness. Results: In total, 4,835 candidate physicians were screened, with 1,701 participants included in the analysis population. Of these, 84.2% had heard of AHA but only 29.7% could identify AHA symptoms and pathologies. More than 45% of participants in the emergency, general medicine, oncology, and rheumatology and collagen medicine departments were familiar with the disease name, symptoms, and pathologies, compared with less than 20% in the geriatrics, neurosurgery, obstetrics and gynecology, orthopedics, respiratory surgery, and urology departments. Although a high proportion (80.4%) of participants reported no experience of examining patients with AHA, many (79.4%) had examined patients exhibiting symptoms of AHA, indicating that they may have encountered patients for whom AHA should have been suspected. When presented with a fictitious AHA case, 44.3% of participants suspected and 34.7% strongly suspected acquired coagulopathy, with substantial variation observed between the different medical departments. Provision of additional laboratory results for the fictitious AHA case increased the proportion of participants who strongly suspected acquired coagulopathy to 38.0%. Conclusions: Awareness of AHA among non-hematologist physicians in Japan is limited and inconsistent across departments. Educational initiatives are needed to enhance awareness and disease-specific knowledge among physicians, particularly those who are most likely to encounter patients with AHA, which is essential for early diagnosis and treatment. UMIN clinical trials registry identification: UMIN000053895.