title: Using routine Haemophilia Joint Health Score for international comparisons of haemophilia outcome: standardization is needed.
abstract: BACKGROUND
  Haemophilia Joint Health Score (HJHS) is the most sensitive validated score for physical examination of joint health in haemophilia. HJHS performed at regular intervals can be used for clinical monitoring as well as for comparative outcomes research.
  
  
  OBJECTIVE
  To determine whether routinely collected HJHS could be used to compare outcome of three different prophylactic regimens in children with severe haemophilia A (primary) and which parameters caused variability in HJHS (secondary).
  
  
  METHODS
  International retrospective observational multi-centre study comparing routine HJHS in 127 children with severe haemophilia A born from 1995 to 2009, from London, Stockholm and Utrecht centres. Patient and treatment data were collected from the European Paediatric Network for Haemophilia Management registry and patient files. The independent effects of regimens, physiotherapists, age and inhibitor status on HJHS were explored, using multivariable regression analysis.
  
  
  RESULTS
  Prophylaxis varied across participating centres, with differences in initial frequency of infusions (1× per week vs. 3× per week), age at reaching infusions ≥3× per week, and dose kg(-1) week(-1) at HJHS assessment. Evaluation at median age of 11 years showed an illogical association of HJHS with treatment regimen: the least intensive regimen had the lowest HJHS. The HJHS increased with age and history of inhibitor, as expected (internal validity). But the comparison of prophylactic regimens was obscured by systematic differences in assessment between physiotherapists, both within and between centres.
  
  
  CONCLUSIONS
  Inter-physiotherapist discrepancies in routine HJHS hamper comparison of scores between treatment regimens. For multi-centre research, additional inter-observer standardization for HJHS scoring is needed.
authors.affiliation: Van Creveldkliniek, Department of Hematology, University Medical Center, Utrecht, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Nijdam
authors.affiliation: Heamophilia Center, Department of Haematology, Great Ormond Street Hospital for Children, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Bladen
authors.affiliation: Heamophilia Center, Department of Haematology, Great Ormond Street Hospital for Children, London, UK.
authors.forename: N
authors.initials: N
authors.lastname: Hubert
authors.affiliation: Paediatric Department of Coagulation Disorders, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Pettersson
authors.affiliation: Child Development and Exercise Center, Wilhelmina Children's Hospital, University Medical Center, Utrecht, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Bartels
authors.affiliation: Child Development and Exercise Center, Wilhelmina Children's Hospital, University Medical Center, Utrecht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van der Net
authors.affiliation: Heamophilia Center, Department of Haematology, Great Ormond Street Hospital for Children, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Liesner
authors.affiliation: Paediatric Department of Coagulation Disorders, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Petrini
authors.affiliation: Dr. von Haunersches Children's Hospital, University of Munich, Munich, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kurnik
authors.affiliation: Van Creveldkliniek, Department of Hematology, University Medical Center, Utrecht, The Netherlands.|Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Fischer
mesh_terms: D000293:Adolescent; D002648:Child; D006467:Hemophilia A / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D038622:Internationality; D007596:Joints; D010808:Physical Examination / Q000592:standards*; D012015:Reference Standards; D012189:Retrospective Studies
keywords: Haemophilia Joint Health Score; arthropathy; inter-observer bias; outcome; physical examination; prophylaxis