Diagnostic accuracy of the OMERACT DC sign for gout with and without dynamic assessment
| Patients with gout | Patients with CPPD | Sensitivity (95% CI) | Specificity (95% CI) | Accuracy (95% CI) | |
| DC sign, static assessment* | 47 (58.0%) | 9 (10.7%) | 58.0% (95% CI 46.5% to 68.9%) | 89.3% (95% CI 80.6% to 95.0%) | 73.9% (95% CI 66.5% to 80.5%) |
| DC sign, static assessment in patients with crystal-proven diagnosis† | 30 (50.8%) | 9 (10.7%) | 50.8% (95% CI 37.5% to 64.1%) | 89.3% (95% CI 80.6% to 95.0%) | 73.4% (95% CI 65.4% to 80.5%) |
| DC sign, static assessment excluding those with the coexistence of the DC sign and CPP deposits within the hyaline cartilage‡ | 47 (58.0%) | 5 (6.3%) | 58.0% (95% CI 46.5% to 68.9%) | 93.8% (95% CI 86.0% to 97.9%) | 75.8% (95% CI 62.9% to 74.1%) |
| DC sign, static assessment excluding those with the coexistence of the DC sign and any CPP deposits in the same joint§ | 45 (57.0%) | 3 (3.8%) | 57.0% (95% CI 45.3% to 68.1%) | 96.2% (95% CI 89.2% to 99.2%) | 76.4% (95% CI 69.0% to 82.8%) |
| DC sign, dynamic assessment | 47 (58.0%) | 2 (2.4%) | 58.0% (95% CI 46.5% to 68.9%) | 97.6% (95% CI 91.7% to 99.7%) | 78.2% (95% CI 71.1% to 84.2%) |
| DC sign, dynamic assessment in patients with crystal-proven diagnosis† | 30 (50.8%) | 2 (2.4%) | 50.8% (95% CI 37.5% to 64.1%) | 97.6% (95% CI 91.7% to 99.7%) | 78.3% (95% CI 70.7% to 84.8%) |
| DC sign, dynamic assessment excluding those with the coexistence of the DC sign and CPP deposits within the hyaline cartilage‡ | 47 (58.0%) | 1 (1.3%) | 58.0% (95% CI 46.5% to 68.9%) | 98.8% (95% CI 93.2% to 99.9%) | 78.3% (95% CI 71.1% to 84.4%) |
| DC sign, dynamic assessment excluding those with the coexistence of the DC sign and any CPP deposits in the same joint§ | 45 (57.0%) | 0 | 57.0% (95% CI 45.3% to 68.1%) | 100% (95% CI 95.4% to 100%) | 78.3% (95% CI 71.1% to 84.5%) |
*Eighty-one patients with gout and 84 patients with CPPD disease were included in the analysis.
†Fifty-nine patients with gout and 84 patients with CPPD disease were included in the analysis.
‡Eighty-one patients with gout and 80 patients with CPPD disease were included in the analysis.
§Seventy-nine patients with gout and 78 patients with CPPD disease were included in the analysis.
CPPD, calcium pyrophosphate deposition; DC, double contour; OMERACT, Outcome Measure in Rheumatology.