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A patient-derived and patient-reported outcome measure for assessing psoriatic arthritis: elaboration and preliminary validation of the Psoriatic Arthritis Impact of Disease (PsAID) questionnaire, a 13-country EULAR initiative
  1. Laure Gossec1,
  2. Maarten de Wit2,
  3. Uta Kiltz3,
  4. Juergen Braun3,
  5. Umut Kalyoncu4,
  6. Rossana Scrivo5,
  7. Mara Maccarone6,
  8. Laurence Carton7,
  9. Kati Otsa8,
  10. Imre Sooäär9,
  11. Turid Heiberg10,
  12. Heidi Bertheussen11,
  13. Juan D Cañete12,
  14. Anselm Sánchez Lombarte13,
  15. Andra Balanescu14,
  16. Alina Dinte15,
  17. Kurt de Vlam16,
  18. Josef S Smolen17,18,
  19. Tanja Stamm18,19,
  20. Dora Niedermayer20,
  21. Gabor Békés21,
  22. Douglas Veale22,
  23. Philip Helliwell23,
  24. Andrew Parkinson24,
  25. Thomas Luger25,
  26. Tore K Kvien26,
  27. On behalf of the EULAR PsAID Taskforce
  1. 1Department of Rheumatology, UPMC University Paris 06, GRC-UPMC 08 (EEMOIS) and AP-HP, Pitié Salpêtrière Hospital, Paris, France
  2. 2Patient Research Partner, People with Arthritis/Rheumatism in Europe (PARE), Zurich, Switzerland
  3. 3Rheumazentrum Ruhrgebiet, Herne and Ruhr-Universität Bochum, Herne, Germany
  4. 4Division of Rheumatology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
  5. 5Dipartimento di Medicina Interna e Specialità Mediche, Reumatologia—Sapienza Università di Roma, Rome, Italy
  6. 6Patient Research Partner, ADIPSO (Associazione per la Difesa degli Psoriasici)—PEPsoPOF (Pan European Psoriasis Patients’ Organization Forum), Rome, Italy
  7. 7Patient Research Partner, Aflar Patient Association, Paris, France
  8. 8Rheumatology Department, Tallinn Central Hospital, Tallinn, Estonia
  9. 9Patient Research Partner, Estonia
  10. 10Faculty of Health and Social Studies, Regional Research Support, Oslo University Hospital, Oestfold University College, Halden, Norway
  11. 11Patient Research Partner, Norway
  12. 12Arthritis Unit, Department of Rheumatology, Hospital Clínic and IDIBAPS, Barcelona, Spain
  13. 13Patient Research Partner, Spain
  14. 14Research Center of Rheumatic Diseases, Sf Maria Hospital, University of Medicine and Pharmacy Carol Davila, Bucharest, Romania
  15. 15Patient Research Partner, Romania
  16. 16Department of Rheumatology, University Hospitals Leuven, Leuven, Belgium
  17. 17Division of Rheumatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
  18. 182nd Department of Medicine, Hietzing Hospital, Vienna, Austria
  19. 19Division of Rheumatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
  20. 203rd Rheumatology Department, National Institute of Rheumatology and Physiotherapy, Budapest, Hungary
  21. 21Patient Research Partner, Hungary
  22. 22Dublin Academic Medical Centre, St Vincent's University Hospital, Dublin, Ireland
  23. 23Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, UK
  24. 24Patient Research Partner, UK
  25. 25Department of Dermatology, University Hospital Münster, Münster, Germany
  26. 26Department of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway
  1. Correspondence to Dr Laure Gossec, Service de Rhumatologie, Hôpital Pitié-Salpétrière, 47-83, boulevard de l'Hôpital, Paris 75013, France; laure.gossec{at}


Introduction The objective was to develop a questionnaire that can be used to calculate a score reflecting the impact of psoriatic arthritis (PsA) from the patients’ perspective: the PsA Impact of Disease (PsAID) questionnaire.

Methods Twelve patient research partners identified important domains (areas of health); 139 patients prioritised them according to importance. Numeric rating scale (NRS) questions were developed, one for each domain. To combine the domains into a single score, relative weights were determined based on the relative importance given by 474 patients with PsA. An international cross-sectional and longitudinal validation study was performed in 13 countries to examine correlations of the PsAID score with other PsA or generic disease measures. Test–retest reliability and responsiveness (3 months after a treatment change) were examined in two subsets of patients.

Results Two PsAID questionnaires were developed with both physical and psychological domains: one for clinical practice (12 domains of health) and one for clinical trials (nine domains). Pain, fatigue and skin problems had the highest relative importance. The PsAID scores correlated well with patient global assessment (N=474, Spearman r=0.82–0.84), reliability was high in stable patients (N=88, intraclass correlation coefficient=0.94–0.95), and sensitivity to change was also acceptable (N=71, standardised response mean=0.90–0.91).

Conclusions A questionnaire to assess the impact of PsA on patients’ lives has been developed and validated. Two versions of the questionnaire are available, one for clinical practice (PsAID-12) and one for clinical trials (PsAID-9). The PsAID questionnaires should allow better assessment of the patient's perspective in PsA. Further validation is needed.

  • patient perspective
  • outcome measure
  • questionnaire
  • patient research partner
  • quality of life
  • response criteria
  • composite criteria
  • pain
  • fatigue

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