Understanding Treatment Care and Delays in Acquired Hemophilia A: A Population-Based Study From Nova Scotia, Canada

Acquired Hemophilia A (AHA) is a rare, potentially life-threatening bleeding disorder caused by autoantibodies against factor VIII (FVIII). We aimed to characterize patients with AHA in Nova Scotia, Canada, and assess diagnostic delays.

We conducted a retrospective, population-based study of adults (≥ 18 years) with AHA treated at the central Hemophilia Treatment Center (HTC) from 2006 to 2024. Demographics, presentation, treatment, outcomes, and diagnostic timelines were reviewed.

Twenty-seven cases were identified, with a mean annual incidence of 1.46 per million. Median age was 74 years (Interquartile range [IQR] 63.5-80); 26% had malignancy and 22% autoimmune disease. All patients received immunosuppressive therapy, and 63% required bypassing agents. Relapsing or refractory disease occurred in 30%. The 5-year overall survival was 48%. Diagnosis was delayed ≥ 7 days in 63% of cases, with median times of 32 days (IQR 4.5-75) from first bleeding and 10 days (IQR 6-45.5) from first elevated PTT. Patients had a median of 2 (IQR 2-5) bleeding-related encounters before diagnosis. Delayed diagnoses were linked to younger age, disease severity, and rural residence.

Despite centralized care, diagnostic delays were frequent, underscoring the need for early coagulation testing in unexplained bleeding.