Article Text

other Versions

Evaluation of the appropriateness of composite Disease Activity measures for assessment of psoriatic arthritis
  1. Valerie P Nell-Duxneuner (valerie.nell{at}
  1. Division of Rheumatology, Medical University and 4th Dep. of Medicine, Hanusch Hospital, Vienna, Austria
    1. Tanja A Stamm
    1. Division of Rheumatology, Medical University of Vienna, Austria
      1. Klaus P Machold
      1. Division of Rheumatology, Medical University of Vienna, Austria
        1. Stephan Pflugbeil
        1. 2nd Dep. of Medicine, Hietzing Hospital, Vienna, Austria
          1. Daniel Aletaha
          1. Division of Rheumatology, Medical University of Vienna, Austria
            1. Josef S Smolen (josef.smolen{at}
            1. Division of Rheumatology, Medical University of Vienna and 2nd Dep. Hietzing Hospital, Vienna, Austria


              Objective: Specific composite indices assessing disease activity in psoriatic arthritis (PsA) have not yet been sufficiently validated. The objective of this study was to identify instruments best reflecting disease activity in PsA.

              Methods: Measures for inclusion in clinical trials, as recommended by the OMERACT-7/8 PsA workshops, were assessed. A principal component analysis (PCA) was performed with cross-sectional data of 105 PsA patients to identify a minimal set of important dimensions for a disease activity assessment tool for PsA. This was compared with components contained in existing composite indices.

              Results: The PCA revealed four principal components best reflecting disease activity. The first contained patient global and pain assessment. The second contained 66/68 swollen and tender joint counts as main variables. C-reactive protein (CRP) best loaded to the third component. The fourth was loaded by skin assessment but did not reach significance. When comparing the three significant principal components with items of established composite measures, they were best covered by the Disease Activity Index for Reactive Arthritis (DAREA), which comprises patient pain and global assessments, 66/68 joint counts, and CRP.

              Conclusion: Among the currently available indices used in arthritic conditions, the DAREA best reflects the domains found to be important in PsA.

              Statistics from

              • Web Only Data ard.2009.117945

                Files in this Data Supplement:

              Request permissions

              If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.