BOSTON — The American College of Rheumatology/European League Against Rheumatism recently came out with new 2015 Gout Classification Criteria.

The effort, led by authors from Boston University and including participation from the Birmingham, AL, VAMC, note, “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 document was published recently in Annals of Rheumatic Diseases.

The international group of investigators 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.

Results formed the basis for developing the classification criteria, which were tested in an independent data set.

Under the new classification, the entry criterion 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 (i.e., synovial fluid) or in a tophus is a sufficient criterion for classification of the subject as having gout and does not require further scoring, according to the guidelines.

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 computed tomography, radiographic gout-related erosion).

The developers reported that the sensitivity and specificity of the criteria are high, 92% and 89%, respectively.

“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,” the authors concluded.

1 Neogi T, Jansen TL, Dalbeth N, Fransen J, et. al. 2015 Gout classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis. 2015 Oct;74(10):1789-98. doi: 10.1136/annrheumdis-2015-208237. Review. PubMed PMID: 26359487; PubMed Central PMCID: PMC4602275