ACR-EULAR Gout Classification Criteria Score
Measured Factor Detail
The ACR-EULAR Gout Classification Criteria provides classification criteria for gout diagnosis. The diagnosis includes episode of swelling/pain/tenderness in a peripheral joint/bursa, presence of monosodium urrate crystals in a symptomatic joint/bursa/tophus, pattern of joint/bursa involvement during episodes, number of characteristics during episodes, number of episodes, evidence of tophus, serum urate levels, synovial fluid analysis, and imaging evidence. A score of 8 or greater indicates positive diagnosis. The ACR-EULAR Gout Classification Criteria Score can be used to diagnose gout when synovial fluid or tophus aspiration is not feasible.
Primary Care Physician
Measured Factor High Impact
- Critical High: Score ≥ 8
- Normal: Score <8
- Normal Adult Male: Score <8
- Normal Adult Female: Score <8
- Normal Geriatric Male: Score <8
- Normal Geriatric Female: Score <8
In clinical practice, joint or tophus aspiration is still the gold standard for the diagnosis of gout. The ACR-EULAR Gout Classification Criteria Score is designed to be used when synovial fluid or tophus aspiration is not feasible. Moreover, the ACR-EULAR Gout Classification Criteria Score are not intended to characterize the severity of gout, but only its presence.
Study Validation 1
This study evaluated evaluate the sensitivity and specificity of the 2015 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) gout classification criteria in 109 gout patients and 74 non-gout patients with acute arthritis condition. Sensitivity and specificity were calculated using the presence of monosodium urate crystals, which is the gold standard for gout diagnosis. The ACR/EULAR classification criteria had high sensitivity (90.2%) and high specificity (90.0%). When synovial fluid microscopy was excluded, the ACR/EULAR classification criteria had 90.2% sensitivity and 85.0% specificity. Clinical-only criteria had 79.8 % sensitivity and 87.8% specificity. The ACR/EULAR classification criteria performed well among patients with early and non-tophaceous disease, but had lower specificity in patients with established disease.
Study Validation 2
This study tested the performance of the 2015 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) gout classification criteria in 381 patients. Diagnostic performance was assessed for the full version of the criteria (including synovial fluid analysis results) and the clinical-only version (not including synovial fluid analysis results). The full and clinical-only versions had area under the receiver operating characteristic curve of 0.96 and 0.87, respectively, with high specificity (0.98 and 0.84), but low sensitivity (0.68 and 0.68). Specificity of both versions were higher compared with the specificity of the 2010 diagnostic decision rule (0.71). The study concluded that the ACR-EULAR gout classification criteria performed well for the purpose of enrolling patients into gout clinical trials.
Study Validation 3
This study aimed at identifying the best-performing survey definition of gout from epidemiologic studies. The simple definition of "self-report of gout or urate-lowering therapy use" had 82% sensitivity and 72% specificity. The data-driven case definition from the study for Updated Gout Classification Criteria had 87% sensitivity and 70% specificity. The 1977 American Rheumatism Association survey criteria had 82% sensitivity and 67% specificity. Finally, the 2015 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) gout classification criteria had the best performance with 92% sensitivity and 89% specificity. The study concluded that the 2015 ACR/EULAR gout classification criteria should be use for a more accurate case definition.
Study Additional 1
The goals of this review study were to compare the diagnostic and classification criteria for gout and to clarify the American College of Rheumatology's position on both types of criteria. Diagnostic criteria are a set of signs, symptoms, and tests used in clinical setting to guide the care of patients. Classification criteria are standardized definitions used in clinical studies to create uniform cohorts with key features of gout. Classification criteria maily require very high specificity, with and without true “gold standards” (e.g., monosodium urate crystals in gout), no or little impact on billing and reimbursement, and no treatment implications for patients. On the other hand, diagnostic criteria mostly require high specificity and sensitivity, true “gold standards” (e.g., monosodium urate crystals in gout), impact on billing and reimbursement, and treatment implications for patients. The American College of Rheumatology will provide approval only for classification criteria and will no longer consider funding or endorsement of diagnostic criteria.