Methods. Eligible patients had been diagnosed by site rheumatologists (termed the "MD diagnosis") since 2004. This diagnosis was used as a reference standard for sensitivity and specificity testing of the 2 WG classification criteria. Descriptive analyses were confined to ACR-classified WG patients.Results. MD diagnoses of 117 patients (82 of whom were female) were WG (n ‫؍‬ 76), microscopic polyangiitis (n ‫؍‬ 17), ANCA-positive pauci-immune glomerulonephritis (n ‫؍‬ 5), Churg-Strauss syndrome (n ‫؍‬ 2), and unclassified vasculitis (n ‫؍‬ 17). The sensitivities of the ACR and EULAR/PRES classification criteria for WG among the spectrum of AAVs were