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Extended report
First step in the development of an ultrasound joint inflammation score for rheumatoid arthritis using a data-driven approach
  1. Anna-Birgitte Aga1,
  2. Hilde Berner Hammer1,
  3. Inge Christoffer Olsen1,
  4. Till Uhlig1,
  5. Tore K Kvien1,
  6. Désirée van der Heijde1,2,
  7. Hallvard Fremstad3,
  8. Tor Magne Madland4,
  9. Åse Stavland Lexberg5,
  10. Hilde Haukeland6,
  11. Erik Rødevand7,
  12. Christian Høili8,
  13. Hilde Stray9,
  14. Anne Noraas Bendvold10,
  15. Dag Magnar Soldal11,
  16. Gunnstein Bakland12,13,
  17. Elisabeth Lie1,
  18. Espen A Haavardsholm1
  1. 1Department of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway
  2. 2Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands
  3. 3Department of Rheumatology, Ålesund Hospital, Helse Møre og Romsdal HF, Ålesund, Norway
  4. 4Department of Rheumatology, Haukeland University Hospital, Helse Bergen HF, Bergen, Norway
  5. 5Department of Rheumatology, Drammen Hospital, Vestre Viken HF, Drammen, Norway
  6. 6Department of Rheumatology, Martina Hansens Hospital AS, Bærum, Norway
  7. 7Department of Rheumatology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
  8. 8Department of Rheumatology, Hospital Østfold HF, Moss, Norway
  9. 9Haugesund Rheumatism HospitalAS, Haugesund, Norway
  10. 10The Rheumatology Clinic Dovland/Bendvold, Kristiansand, Norway
  11. 11Department of Rheumatology, Sørlandet Hospital HF, Kristiansand, Norway
  12. 12Department of Rheumatology, University Hospital of North Norway, Tromsø, Norway
  13. 13Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway
  1. Correspondence to Dr Anna-Birgitte Aga, Department of Rheumatology, Diakonhjemmet Hospital, P.O. Box 23 Vinderen, Oslo N-0319, Norway; anna.birgitte.aga{at}


Objectives To develop and validate candidate sets of joints and tendons for assessment of ultrasound (US) joint inflammation in rheumatoid arthritis (RA).

Methods Patients were included in one of two cohorts from 2010 to June 2013: disease-modifying antirheumatic drug naïve early RA or established RA starting/switching biologics. An extensive US examination was performed by experienced sonographers using a validated grey-scale (GSUS) and power Doppler (PDUS) semiquantitative scoring system with scores 0–3 for both GSUS and PDUS in 36 joints and four tendons. We performed factor analysis in the early RA US data and selected candidate joint/tendon sets based on these results. The proportion of information in the total US scores retained in these candidate sets was assessed by R2 from linear regression analysis. Finally, the candidate sets and previously proposed joint scores were tested in the established RA cohort, and we also evaluated the sensitivity to change with standardised response means.

Results 227 patients with early RA and 212 patients with established RA were included. We identified two candidate sets of joints/tendons: candidate set A consisted of seven joints/two tendons (meatacarpophalangeal 1 (MCP1), MCP2, proximal interphalangeal 3, radiocarpal, elbow, metatarsophalangeal 1 (MTP1), MTP2, tibialis posterior tendon, extensor carpi ulnaris tendon) and set B of nine joints/two tendons (MCP5 and MTP5 added to set A). Unilateral reduced scores retained 78%–85% of the information in total score, while bilateral reduced scores retained 89%–93%, and both sets performed better than previously proposed reduced joint scores, and similar or slightly better regarding sensitivity to change.

Conclusions The reduced GSUS and PDUS scores retained most of the information from the total score and performed well in a validation cohort of established RA.

Trial registation number NCT01205854, ACTRN12610000284066.

  • Rheumatoid Arthritis
  • Ultrasonography
  • Disease Activity

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