BeneFIX Drug Use Results Survey [All-Case Surveillance]

Patients with hemophilia B (congenital blood coagulation factor IX deficiency) who are administered this drug. Patients with hemophilia B are either patients for whom treatment was already started with a blood coagulation factor IX product ("Previously treated patients": hereinafter, "PTPs") or patients who have no history of treatment with a blood coagulation factor IX product in the past and for whom treatment will be started with this drug for the first time ("Previously untreated patients": hereinafter, "PUPs"). The definition of PUPs in this survey is "Patients in whom the total number of days of administration of a blood coagulation factor IX product other than this drug before administration of this drug was 3 exposure days (actual number of days of administration: hereinafter, "EDs") or less."