TABLE 2.
Summary of the clinical performance of Portrait Staph ID/R BCP versus cefoxitin disk diffusion test method for the detection of methicillin resistance in 762 prospective blood culturesa
| Result, all sites combined, for detection of methicillin resistance | % Agreement |
|||
|---|---|---|---|---|
| TP/TP + FN | PPA (95% CI) | TN/TN + FP | NPA (95% CI) | |
| S. aureus | 72/75 | 96.0 (86.6–97.8) | 682/687 | 99.3 (98.3–99.7) |
| S. lugdunensis | 0/0 | NA | 762/762 | 100 (99.5–100) |
| Staphylococcus spp. other than S. aureus or S. lugdunensis | 247/263 | 93.9 (90.3–96.2) | 481/499 | 96.4 (94.4–97.7) |
a
Three culture isolates of Staphylococcus failed to grow on Mueller-Hinton agar for cefoxitin testing. TP, true positive; TN, true negative; FP, false positive; FN, false negative; PPA, positive percent agreement; NPA, negative percent agreement; CI, confidence interval. NA, not applicable.