Diagnostic performance of nested PCR on lung tissue specimens by the diagnostic standards used for pulmonary tuberculosis(TB)
| Diagnostic standards | TB | Not TB | Total | Sensitivity | Specificity | PPV | NPV |
| Mycobacterial culture# | 85 (80–86) | 99 (95–100) | 98 (93–100) | 88 (84–89) | |||
| PCR positive | 60 | 1§ | 61 | ||||
| PCR negative | 11 | 80 | 91 | ||||
| Total | 71 | 81 | 152 | ||||
| Mycobacterial culture or histopathology¶ | 78 (74–79) | 99 (94–100) | 99 (94–100) | 79(76–80) | |||
| PCR positive | 74 | 1§ | 75 | ||||
| PCR negative | 21 | 80 | 101 | ||||
| Total | 95 | 81 | 176 | ||||
| Mycobacterial culture, histopathology or medication response+ | 66 (63–67) | 99 (94–100) | 99 (95–100) | 63 (59–63) | |||
| PCR positive | 94 | 1§ | 95 | ||||
| PCR negative | 48 | 80 | 128 | ||||
| Total | 142 | 81 | 223 |
Data are presented as n or % (95% CI). PPV: positive predictive value; NPV: negative predictive value. #: culture-positive: definite TB; ¶: typical histopathological findings for TB with good response to TB medication: probable TB; +: good response to TB medication with culture negative and atypical histopathological findings: possible TB; §: one case of a lung abscess.