TABLE 3.
Routine culture versus Cellenium system results (gram-negative organisms)
| Cellenium system result | No. of specimens with the following culture resulta:
|
|
|---|---|---|
| Positive | Negative | |
| Positive | 124 (TP) | 23 (FP) |
| Negative | 4 (FN) | 612 (TN) |
a
TP, true positive; FN, false negative; TN, true negative; FP, false positive. Sensitivity = TP/(TP + FN) = 124/(124 + 4) = 96.9%; specificity = TN/(TN + FP) = 612/(612 + 23) = 96.4%; PPV = TP/(TP + FP) = 124/(124 + 23) = 84.4%; NPV = TN/(TN + FN) = 612/(612 + 4) = 99.4%.