Health Related Quality of Life of Youth and Young Adults With Hemophilia A

Inclusion Criteria: * Moderate or severe Hemophilia A (factor level ≤5%) * Receiving Helixate FS as on-demand treatment or prophylaxis therapy at time of informed consent * Patient age 14 to 29 years at the time of recruitment * Complete informed consent process and documentation; (Patients under age 18 must assent in addition to consent of legal guardian) * Willing/able to follow study protocol, including keeping a bleeding and treatment diary * Able to communicate clearly in either English or French - both written and verbal communication is essential. Exclusion Criteria: * Known inhibitor at time of recruitment (\> 0,5 Bethesda units) or immune tolerance therapy at time of recruitment * HIV positive * Symptomatic Hepatitis B or C infection or active treatment for hepatitis B or C * Inability to comply with study protocol * Hypersensitivity to Helixate FS or to any ingredients in the formulation or component of the container * Hypersensitivity to mouse or hamster protein * Unsuitable to participate in study for any other reason as assessed by investigator