Comparison of results by sputum smear culture on tuberculosis (TB) and real-time PCR Xpert MTB/RIF in a total of 707 patients in 2012/2013
| Test and result | TB culture-positive | TB culture-negative | Sensitivity | Specificity | PPV | NPV |
| Sputum smear | 64.75 (56.20–72.66) | 99.12 (97.96–99.71) | 94.74 (88.14–98.27) | 91.99 (89.55–94.02) | ||
| Positive | 90 | 5# | ||||
| Negative | 49 | 563 | ||||
| Xpert MTB/RIF | ||||||
| Overall | 90.65 (84.54–94.93) | 98.77 (97.48–99.50) | 94.74 (89.46–97.86) | 97.74 (96.16–98.79) | ||
| Positive | 126 | 7 | ||||
| Negative | 13 | 561 | ||||
| Smear-positive | 100.0 (95.98–100.00) | 100.00 (87.66–100.00) | 100.00 (95.98–100.0) | 100.00 (47.82–100.00) | ||
| Positive | 90 | 0 | ||||
| Negative | 0 | 5 | ||||
| Smear-negative | 73.47 (58.92–85.05) | 98.76 (97.46–99.50) | 83.72 (69.30–93.19) | 97.72 (96.12–98.78) | ||
| Positive | 36 | 7 | ||||
| Negative | 13 | 556 |
Data are presented as n or % (95% CI). NPV: negative predictive value; PPV: positive predictive value. #: samples from patients suffering from nontuberculous mycobacterial disease.