Table 1. Discrimination Statistics for Published Diagnostic Criteria for Ulcerative Pyoderma Gangrenosuma.
Diagnostic criteria | Mean (SE) [95% CI], % | AUC (95% CI)b | Correctly classified, % | |
---|---|---|---|---|
Sensitivity | Specificity | |||
Su et al2 | ||||
Complete case data | 86.21 (0.05) [77.33-95.08] | 69.57 (0.07) [56.27-82.86] | 0.74 (0.67-0.81) | 78.21 |
Imputed case data | 86.39 (0.04) [79.32-93.46] | 70.41 (0.06) [59.50-81.31] | NA | 79.41 |
Delphi3 | ||||
Complete case data | 88.00 (0.05) [78.99-97.01] | 90.48 (0.05) [81.60-99.35] | 0.89 (0.83-0.94) | 89.13 |
Imputed case data | 86.72 (0.05) [77.26-96.18] | 90.49 (0.05) [81.10-99.89] | NA | 89.07 |
PARACELSUS4 | ||||
Complete case data | 95.89 (0.02) [91.33-100] | 4.65 (0.03) [0-10.95] | 0.55 (0.48-0.62) | 61.02 |
Imputed case data | 91.31 (0.03) [85.48-97.15] | 14.36 (0.06) [2.25-26.48] | NA | 60.36 |
P valuesc | ||||
Su et al vs Delphi | .02 | <.001 | <.001 | <.001 |
Su et al vs PARACELSUS | .001 | <.001 | <.001 | <.001 |
Delphi vs PARACELSUS | .001 | <.001 | <.001 | <.001 |
Abbreviations: AUC, area under receiver operating characteristic curve; NA, not applicable.
Case data were considered complete when all information was available to fully score all 3 diagnostic criteria (see eMethods in the Supplement). Missing data were accounted for using the multiple imputation by chained equations framework under both missing completely at random and missing at random assumptions (imputed case data). Cases included the following published diagnostic categories: vascular occlusive or venous, 19; primary infection, 16; cancer, 16; drug-induced or exogenous injury, 7; calciphylaxis, 6; and vasculitis, 5.
AUC is a value that measures the overall diagnostic performance of a binary classifier (eg, a set of diagnostic criteria). An AUC value of 0.5 indicates that the diagnostic criteria have no discriminatory ability (random classifier), and an AUC value of 1.0 indicates perfect discriminatory ability (perfect classifier).
P values for sensitivity and specificity were calculated with a 2-sided McNemar test. P values for AUCs were calculated using the DeLong nonparametric approach for comparing AUCs under 2 or more receiver operating characteristic curves.