Table 2 2 × 2 contingency table for statistical calculation of SEN, SP, PPV and NPV for the detection of a positive A. pleuropneumoniae lung colonization status by bacteriological culture examination of tonsilar samples (n = 163)
Samples positive by lung tissue examination | Samples negative by lung tissue examination | |
|---|---|---|
Samples positive by tonsil examination | 122 (true positive) | 7 (false positive) |
Samples negative by tonsil examination | 22 (false negative) | 12 (true negative) |
Sensitivity (SEN) | true positive / (true positive + false negative) = | 84.72% |
Specificity (SP) | true negative / (true negative + false positive) = | 63.16% |
Positive predictive value (PPV) | true positive /(true positive + false positive)= | 94.57% |
Negative predictive value (NPV) | True negative / (true negative + false negative) = | 35.29% |