RT Journal Article SR Electronic T1 2015 Gout classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 1789 OP 1798 DO 10.1136/annrheumdis-2015-208237 VO 74 IS 10 A1 Tuhina Neogi A1 Tim L Th A Jansen A1 Nicola Dalbeth A1 Jaap Fransen A1 H Ralph Schumacher A1 Dianne Berendsen A1 Melanie Brown A1 Hyon Choi A1 N Lawrence Edwards A1 Hein J E M Janssens A1 Frédéric Lioté A1 Raymond P Naden A1 George Nuki A1 Alexis Ogdie A1 Fernando Perez-Ruiz A1 Kenneth Saag A1 Jasvinder A Singh A1 John S Sundy A1 Anne-Kathrin Tausche A1 Janitzia Vaquez-Mellado A1 Steven A Yarows A1 William J Taylor YR 2015 UL http://ard.bmj.com/content/74/10/1789.abstract AB Objective Existing criteria for the classification of gout have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout.Methods An international group of investigators, supported by the American College of Rheumatology and the European League Against Rheumatism, conducted a systematic review of the literature on advanced imaging of gout, a diagnostic study in which the presence of monosodium urate monohydrate (MSU) crystals in synovial fluid or tophus was the gold standard, a ranking exercise of paper patient cases, and a multi-criterion decision analysis exercise. These data formed the basis for developing the classification criteria, which were tested in an independent data set.Results The entry criterion for the new classification criteria requires the occurrence of at least one episode of peripheral joint or bursal swelling, pain, or tenderness. The presence of MSU crystals in a symptomatic joint/bursa (ie, synovial fluid) or in a tophus is a sufficient criterion for classification of the subject as having gout, and does not require further scoring. The domains of the new classification criteria include clinical (pattern of joint/bursa involvement, characteristics and time course of symptomatic episodes), laboratory (serum urate, MSU-negative synovial fluid aspirate), and imaging (double-contour sign on ultrasound or urate on dual-energy CT, radiographic gout-related erosion). The sensitivity and specificity of the criteria are high (92% and 89%, respectively).Conclusions The new classification criteria, developed using a data-driven and decision-analytic approach, have excellent performance characteristics and incorporate current state-of-the-art evidence regarding gout.