title: Defining criteria for high disease activity in juvenile idiopathic arthritis based on the juvenile arthritis disease activity score.
abstract: OBJECTIVE
  To determine cutoff values for defining the state of high disease activity (HDA) in juvenile idiopathic arthritis (JIA) using the Juvenile Arthritis Disease Activity Score (JADAS).
  
  
  METHODS
  For the selection of cutoff values, data from a clinical database including 609 patients were used. Optimal cutoff values were determined against external criteria by calculating the 25th and 10th centile of cumulative score distribution and through receiver operating characteristic curve analysis. External criteria were based on the therapeutic decision made by the attending doctor. Cross-validation was performed using five patient samples that included 1421 patients.
  
  
  RESULTS
  The optimal cutoff values were those obtained through the 90% fixed sensitivity method. The selected JADAS cutoff values were the following: 4.2 and 8.5 for JADAS27 in oligoarthritis and polyarthritis, respectively; 4.2 and 10.5 for both JADAS10 and JADAS71 in oligoarthritis and polyarthritis, respectively. In cross-validation analyses, the cutoff values showed strong ability to discriminate between different levels of American College of Rheumatology paediatric response in two clinical trials and could predict worse functional and radiographic outcome.
  
  
  CONCLUSIONS
  Cutoff values for classifying HDA in JIA using the JADAS were developed. In cross-validation analyses, they proved to have good construct and discriminant validity and ability to predict disease outcome.
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Consolaro
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Nicolino
authors.initials: N
authors.lastname: Ruperto
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Bracciolini
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Frisina
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Gallo
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Pistorio
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Verazza
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Negro
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Gerloni
authors.affiliation: Istituto Gaetano Pini, Milano, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Goldenstein-Schainberg
authors.affiliation: Faculdade de Medicina da Universidade de São Paulo, São Paulo/SP, Brazil.
authors.forename: Flavio
authors.initials: F
authors.lastname: Sztajnbok
authors.affiliation: Universidade do Estado do Rio de Janeiro, Brazil.
authors.forename: Nico M
authors.initials: NM
authors.lastname: Wulffraat
authors.affiliation: Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht, The Netherlands Università degli Studi di Genova, Genova, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Martini
authors.affiliation: Istituto Giannina Gaslini, Genova, Italy Università degli Studi di Genova, Genova, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Ravelli
mesh_terms: D001171:Arthritis, Juvenile / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D001799:Blood Sedimentation; D002648:Child; D006801:Humans; D012372:ROC Curve; D012720:Severity of Illness Index