Table 3 AFB smear microscopy performance for PTB and EPTB in relation to LJ culture as the reference standard
AFB smear microscopy | LJ Culture | |||
|---|---|---|---|---|
PTB (n = 449) | EPTB (n = 133) | |||
Positive (n = 122) | Negative (n = 327) | Positive (n = 38) | Negative (n = 95) | |
Positive | 88 | 61 | 24 | 28 |
Negative | 34 | 266 | 14 | 67 |
Sensitivity | 72.1% | 63.2% | ||
Specificity | 81.3% | 70.5% | ||
PPV | 59.1% | 46.2% | ||
NPV | 88.7% | 82.7% | ||
False -positive rate | 18.7% | 29.5% | ||
False- negative rate | 27.9% | 36.8% | ||
Accuracy | 78.8% | 68.4 % | ||