Canadian CHO-KLAT/H-FIT Study - Quality of Life of, and Burden of Caring for, Persons With Hemophilia

Inclusion Criteria: * Boys with moderate/severe hemophilia A, with or without FVIII inhibitors, age 7-18 years, * Group A: who have previously received prophylaxis with SHL or EHL CFCs at least once a week for the previous year who plan on switching or who have switched to emicizumab. * Group B: who are currently receiving prophylaxis at least once a week for the previous year with any form of treatment other than emicizumab who are not switching treatment regimens. * Group C: who have not been on long-term prophylaxis for the year prior to study commencement who begin prophylactic treatment with emicizumab (i.e., previously untreated patients or patients receiving treatment on demand). * Group D: boys with moderate/severe hemophilia A who have neutralizing alloantibodies to FVIII (FVIII inhibitors), defined as a level of ≥0.6 Bethesda Units (BU) using the Nijmegen modification of the Bethesda assay on two separate occasions within a 1-4 week period1, who are receiving a by-passing hemostatic agent such as a non-activated or activated plasma-derived, virus-inactivated prothrombin complex clotting factor concentrate (e.g., FEIBA), recombinant FVIIa (Niastase), or emicizumab. FVIII Inhibitors of \<5 BU are considered low titer and those ≥5 BU are considered high titer. * Parents/caregivers of boys with moderate/severe hemophilia A with or without FVIII inhibitors between the ages of 0-18 years. * Moderate or severe hemophilia A, defined as FVIII activity level ≤5%. * …