title: Simplified versions of the original disease activity score: validation in the BeSt trial.
abstract: OBJECTIVE
  To evaluate three disease activity score (DAS) alternatives without the Ritchie articular index (RAI). To compare the use of patient global assessment (PGA) of disease activity versus global assessment of health (GH) in DAS, DAS alternatives and DAS28.
  
  
  METHODS
  Data from the BeSt study were used, a treatment strategy trial in early rheumatoid arthritis patients aiming at a DAS ≤2.4. DAS alternatives were DAS 0-1, with the RAI (0-3) reduced to a no-yes (0-1) score, DAS tender joint count 53 (DAS TJC53), with a 0-1 TJC in 53 separate joints and DAS TJC44 in 44 joints. Correlation patterns, mean difference from original DAS, classification differences in disease activity level and patient percentages with radiological damage progression per level were determined for all scores.
  
  
  RESULTS
  In the majority of patients the scores were equal and correlation was high. Mean difference with the DAS at year 1 was -0.03 for DAS 0-1, 0.18 for DAS TJC53 and 0.11 for DAS TJC44. Classification agreement between scores was high (κ year 1 0.76-0.98). Patient percentages with joint damage progression were similar for all scores. DAS, DAS alternative and DAS28 perform similarly using either PGA or GH.
  
  
  CONCLUSIONS
  DAS without the RAI perform comparably to the original DAS and may be chosen as alternatives. PGA can replace GH in the DAS, the alternatives and DAS28.
authors.affiliation: Leiden University Medical Centre, Leiden, The Netherlands. r.koevoets@lumc.nl
authors.forename: R
authors.initials: R
authors.lastname: Koevoets
authors.forename: N B
authors.initials: NB
authors.lastname: Klarenbeek
authors.forename: M
authors.initials: M
authors.lastname: Güler-Yüksel
authors.forename: M
authors.initials: M
authors.lastname: van Oosterhout
authors.forename: M V
authors.initials: MV
authors.lastname: van Krugten
authors.forename: P J S M
authors.initials: PJ
authors.lastname: Kerstens
authors.forename: T W J
authors.initials: TW
authors.lastname: Huizinga
authors.forename: B A C
authors.initials: BA
authors.lastname: Dijkmans
authors.forename: D M F M
authors.initials: DM
authors.lastname: van der Heijde
authors.forename: C F
authors.initials: CF
authors.lastname: Allaart
mesh_terms: D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012074:Remission Induction; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents