Table 8.
Usefulness of screening methods with tests 1 and 2.
| (CI 95%) | Test 1 | Test 2 | ||
|---|---|---|---|---|
| Indicators | AmpC ± ESBL | AmpC Alone | AmpC ± ESBL | AmpC Alone |
| Prevalence | 15.7% | 9.5% | 15.7% | 9.5% |
| Sensitivity | 31.3% (14.2–55.6) | 55.6% (26.7–81.1) | 62.5% (38.6–81.5) | 88.9% (56.5–98) |
| Specificity | 100% (95.7–100) | 100% (95.7–100) | 100% (95.7–100) | 100% (95.7–100) |
| PPV | 100% (56.6–100) | 100 (55.6–100) | 100% (72.2–100) | 100% (67.6–100) |
| NPV | 88.7% (80.8–93.5) | 95.6% (89.1–98.3) | 93.5% (86.5–97) | 98.9% (93.8–99.8) |
| Validity Index | 89.2% (81.7–93.9) | 95.8% (89.7–98.4) | 94.1% (87.8–97.3) | 98.9% (94.3–99.8) |
| Youden’s Index | 0.313 | 0.556 | 0.625 | 0.889 |
PPV: positive predictive value; NPV: negative predictive value; ESBL: extended-spectrum beta-lactamase; CI: confidence interval.