title: A survey of factor prophylaxis in boys with haemophilia followed in North American haemophilia treatment centres.
abstract: A survey was conducted in 2002 to determine the pattern of factor prophylaxis use in boys <or=18 years of age with haemophilia followed in North American treatment centres. Responses were obtained from 4553 cases (74% haemophilia A, 26% haemophilia B). The frequency of prophylaxis, defined as factor infusion greater than or equal to once per week for >or=45 weeks per year, was significantly higher for haemophilia A vs. haemophilia B cases (51% vs. 32%, P< 0.0001), and for boys with severe haemophilia A living in Canada vs. the USA (77% vs. 47%, P< 0.0001). Use of full-dose prophylaxis, defined as the infusion of 25-40 IU kg(-1) of factor VIII on alternate days (minimum three times per week) or 25-40 IU kg(-1) of factor IX twice weekly, was similar for boys <or=5 years of age in both Canada and the USA (30% and 33% haemophilia A and 35% and 13% haemophilia B). Reasons for initiating prophylaxis included a history of joint bleeding (88%) and age <or=2 years (23%). For prophylaxis triggered by joint bleeding, 38% of haemophilia treatment centres indicated that they would initiate prophylaxis after the first joint bleed and 66% after a history of target joint bleeding, defined most frequently as 2-4 bleeds over a 3-6 consecutive month period. A central venous line was used to ensure easy venous access for full-dose prophylaxis therapy in 80% of boys <or=5 years of age. These data offer a basis for projecting long-term factor concentrate needs for persons with haemophilia living in North America.
authors.affiliation: Division of Hematology/Oncology, The Hospital for Sick Children, Toronto and the Department of Pediatrics, University of Toronto, Ontario, Canada. victor.blanchette@sickkids.ca
authors.forename: V S
authors.initials: VS
authors.lastname: Blanchette
authors.forename: M
authors.initials: M
authors.lastname: McCready
authors.forename: C
authors.initials: C
authors.lastname: Achonu
authors.forename: M
authors.initials: M
authors.lastname: Abdolell
authors.forename: G
authors.initials: G
authors.lastname: Rivard
authors.forename: M J
authors.initials: MJ
authors.lastname: Manco-Johnson
mesh_terms: D000293:Adolescent; D002170:Canada; D002405:Catheterization, Central Venous; D002648:Child; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D003657:Decision Making; D006306:Health Surveys; D006467:Hemophilia A / Q000517:prevention & control*; D002836:Hemophilia B / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D014481:United States