title: Composite disease activity and responder indices for psoriatic arthritis: a report from the GRAPPA 2013 meeting on development of cutoffs for both disease activity states and response.
abstract: OBJECTIVE
  There are several new composite indices for assessing disease activity in psoriatic arthritis (PsA). Each may function as a disease state variable and a responder index. The aim of our study was to determine cutoffs for disease activity and response.
  
  
  METHODS
  Data from the Group for GRAPPA Composite Exercise (GRACE) study were used to develop cutoffs using a number of different approaches. Voting on choice of cutoff was undertaken at the 2013 GRAPPA Annual Meeting in Toronto, Ontario, Canada.
  
  
  RESULTS
  After voting, results for cutoffs for low/high disease activity for the Psoriatic ArthritiS Disease Activity Score (PASDAS), GRAppa Composite scorE (GRACE index), and Composite Psoriatic Disease Activity Index (CPDAI), respectively, were 3.2/5.4, 2.3/4.7, and 4/8. The measurement error for each composite score was estimated at 0.8, 1, and 2 for PASDAS, GRACE, and CPDAI, respectively.
  
  
  CONCLUSIONS
  Response criteria for the new composite indices have been developed. These now require further validation and testing in other datasets.
authors.affiliation: From the University of Leeds, Leeds, UK, and Bradford Hospitals National Health Service (NHS) Foundation Trust, Bradford, UK; Department of Rheumatology, St. Vincent's University Hospital, Elm Park, Dublin, Ireland; Department of Rheumatology, Radboud University Medical Centre, Nijmegen, The Netherlands.P.S. Helliwell, DM, PhD, FRCP, Senior Lecturer in Rheumatology, University of Leeds and Bradford Hospitals NHS Foundation Trust; O. FitzGerald, MD, FRCPI, FRCP(UK), Newman Clinical Research Professor, Department of Rheumatology, St. Vincent's University Hospital; J. Fransen, PhD, Department of Rheumatology, Radboud University Medical Centre. p.helliwell@leeds.ac.uk.
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Helliwell
authors.affiliation: From the University of Leeds, Leeds, UK, and Bradford Hospitals National Health Service (NHS) Foundation Trust, Bradford, UK; Department of Rheumatology, St. Vincent's University Hospital, Elm Park, Dublin, Ireland; Department of Rheumatology, Radboud University Medical Centre, Nijmegen, The Netherlands.P.S. Helliwell, DM, PhD, FRCP, Senior Lecturer in Rheumatology, University of Leeds and Bradford Hospitals NHS Foundation Trust; O. FitzGerald, MD, FRCPI, FRCP(UK), Newman Clinical Research Professor, Department of Rheumatology, St. Vincent's University Hospital; J. Fransen, PhD, Department of Rheumatology, Radboud University Medical Centre.
authors.forename: Oliver
authors.initials: O
authors.lastname: FitzGerald
authors.affiliation: From the University of Leeds, Leeds, UK, and Bradford Hospitals National Health Service (NHS) Foundation Trust, Bradford, UK; Department of Rheumatology, St. Vincent's University Hospital, Elm Park, Dublin, Ireland; Department of Rheumatology, Radboud University Medical Centre, Nijmegen, The Netherlands.P.S. Helliwell, DM, PhD, FRCP, Senior Lecturer in Rheumatology, University of Leeds and Bradford Hospitals NHS Foundation Trust; O. FitzGerald, MD, FRCPI, FRCP(UK), Newman Clinical Research Professor, Department of Rheumatology, St. Vincent's University Hospital; J. Fransen, PhD, Department of Rheumatology, Radboud University Medical Centre.
authors.forename: Jaap
authors.initials: J
authors.lastname: Fransen
mesh_terms: D018501:Antirheumatic Agents / Q000627:therapeutic use*; D015535:Arthritis, Psoriatic / Q000175:diagnosis* / Q000188:drug therapy*; D006801:Humans; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents
keywords: COMPOSITE DISEASE ACTIVITY INDEX; OUTCOME MEASURES; PSORIATIC ARTHRITIS; RESPONSE MEASURE