PT  - JOURNAL ARTICLE
AU  - Terslev, Lene
AU  - Gutierrez, Marwin
AU  - Schmidt, Wolfgang A.
AU  - Keen, Helen I.
AU  - Filippucci, Emilio
AU  - Kane, David
AU  - Thiele, Ralf
AU  - Kaeley, Gurjit
AU  - Balint, Peter
AU  - Mandl, Peter
AU  - Delle Sedie, Andrea
AU  - Hammer, Hilde Berner
AU  - Christensen, Robin
AU  - Möller, Ingrid
AU  - Pineda, Carlos
AU  - Kissin, Eugene
AU  - Bruyn, George A.
AU  - Iagnocco, Annamaria
AU  - Naredo, Esperanza
AU  - D’Agostino, Maria Antonietta
TI  - Ultrasound as an Outcome Measure in Gout. A Validation Process by the OMERACT Ultrasound Working Group
AID  - 10.3899/jrheum.141294
DP  - 2015 Sep 01
TA  - The Journal of Rheumatology
PG  - jrheum.141294
4099  - http://www.jrheum.org/content/early/2015/08/26/jrheum.141294.short
4100  - http://www.jrheum.org/content/early/2015/08/26/jrheum.141294.full
AB  - Objective To summarize the work performed by the Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group on the validation of US as a potential outcome measure in gout. Methods Based on the lack of definitions, highlighted in a recent literature review on US as an outcome tool in gout, a series of iterative exercises were carried out to obtain consensus-based definitions on US elementary components in gout using a Delphi exercise and subsequently testing these definitions in static images and in patients with proven gout. Cohen’s κ was used to test agreement, and values of 0–0.20 were considered poor, 0.20–0.40 fair, 0.40–0.60 moderate, 0.60–0.80 good, and 0.80–1 excellent. Results With an agreement of > 80%, consensus-based definitions were obtained for the 4 elementary lesions highlighted in the literature review: tophi, aggregates, erosions, and double contour (DC). In static images interobserver reliability ranged from moderate to almost perfect, and similar results were found for the intrareader reliability. In patients the intraobserver agreement was good for all lesions except DC (moderate). The interobserver agreement was poor for aggregates and DC but moderate for the other components. Conclusion These first steps in evaluating the validity of US as an outcome measure for gout show that the reliability of the definitions ranged from moderate to excellent in static images and somewhat lower in patients, indicating that a standardized scanning technique may be needed, before testing the responsiveness of those definitions in a composite US score.