TABLE 2.
Performance of assays for the detection of CDAD
| Assay | Result | No. of specimens from patients with CDAD:
|
Performance characteristica (%)
|
|||||
|---|---|---|---|---|---|---|---|---|
| Positive | Negative | Sens | Spec | PPV | NPV | Accuracy | ||
| Cytotoxin | Positive | 50 | 8 | 87.7 | 98.6 | 86.2 | 98.8 | 97.6 |
| Negative | 7 | 573 | ||||||
| Toxigenic culture | Positive | 54 | 8 | 94.7 | 98.6 | 87.1 | 99.5 | 98.3 |
| Negative | 3 | 573 | ||||||
| Immunocard | Positive | 41 | 4 | 71.9 | 99.3 | 91.1 | 97.3 | 96.8 |
| Negative | 16 | 577 | ||||||
| Culturette EIA | Positive | 39 | 5 | 68.4 | 99.1 | 88.6 | 96.9 | 96.8 |
| Negative | 18 | 576 | ||||||
a
Sens, sensitivity; Spec, specificity; PPV, positive predictive value; NPV, negative predictive value.