title: Factors associated with choice of biologic among children with Juvenile Idiopathic Arthritis: results from two UK paediatric biologic registers.
abstract: The objectives of this study were to describe patients starting first-line biologics for JIA, to describe characteristics over time among patients starting etanercept, and to describe patterns of second biologic prescribing.
  
  
  
  The British Society for Paediatric and Adolescent Rheumatology Etanercept Cohort Study, and the Biologics for Children with Rheumatic Diseases study are ongoing prospective observational cohorts, collecting data on patients starting biologic therapy for JIA. Patients registered from 1 January 2010 starting their first biologic were compared between therapies. Patients starting etanercept before 2010 were included to analyse changes in etanercept prescribing. The pathway of patients starting a second biologic was recorded in all patients.
  
  
  
  To 26 August 2014, 931 patients were recruited starting a first-line biologic (142 Biologics for Children with Rheumatic Diseases; 789 British Society for Paediatric and Adolescent Rheumatology Etanercept Cohort Study). From 2010, patients with systemic JIA (sJIA) were almost exclusively prescribed anakinra or tocilizumab. Choice between anti-TNF therapies was largely driven by history of chronic anterior uveitis (CAU). When investigating trends in patients starting etanercept over time, disease duration at etanercept start, patients with sJIA, a history of CAU, and those who received concomitant oral corticosteroids decreased over time. Patients who started a second biologic from 1 January 2010 showed a similar stratification.
  
  
  
  Although etanercept remains the most common biologic prescribed for JIA, there has been a clear shift towards the use of alternative biologics, largely driven by disease subtype and history of CAU. This channelling of children towards specific therapies should be considered carefully in future studies and in clinical guidelines and ongoing research.
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Manchester Academic Health Science Centre, The University of Manchester, Manchester.
authors.forename: Lianne
authors.initials: L
authors.lastname: Kearsley-Fleet
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Manchester Academic Health Science Centre, The University of Manchester, Manchester.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Davies
authors.affiliation: Clinical Academic Department of Paediatric Rheumatology.
authors.forename: Eileen
authors.initials: E
authors.lastname: Baildam
authors.affiliation: Clinical Academic Department of Paediatric Rheumatology, Institute of Translational Medicine (Child Health), University of Liverpool, Alder Hey Children's NHS Foundation Trust, Liverpool.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Beresford
authors.affiliation: Musculoskeletal Research Group, Institute Cellular Medicine, Newcastle University, Newcastle upon Tyne.
authors.forename: Helen E
authors.initials: HE
authors.lastname: Foster
authors.affiliation: Department of Paediatric Rheumatology, Institute of Child Health, Birmingham Children's Hospital - NHS Trust and University of Birmingham, Birmingham.
authors.forename: Taunton R
authors.initials: TR
authors.lastname: Southwood
authors.affiliation: Arthritis Research UK Centre for Genetics and Genomics, Manchester Academic Health Science Centre and NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust and University of Manchester Partnership, Manchester, UK.
authors.forename: Wendy
authors.initials: W
authors.lastname: Thomson
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Manchester Academic Health Science Centre, The University of Manchester, Manchester, NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust and University of Manchester Partnership, Manchester, UK kimme.hyrich@manchester.ac.uk.
authors.forename: Kimme L
authors.initials: KL
authors.lastname: Hyrich
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D000293:Adolescent; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000188:drug therapy*; D001685:Biological Factors / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D000066491:Clinical Decision-Making; D057915:Drug Substitution; D005260:Female; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use; D053590:Interleukin 1 Receptor Antagonist Protein / Q000627:therapeutic use; D008297:Male; D011446:Prospective Studies; D012042:Registries
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D001685:Biological Factors; D053590:Interleukin 1 Receptor Antagonist Protein; D000069285:Infliximab; D000068879:Adalimumab; C502936:tocilizumab
keywords: Juvenile Idiopathic Arthritis; attitude of health professionals; biological therapies; epidemiology; information science