Table 3. Accuracy of MTBC RD qPCR assay, smear microscopy and culture.
| Sensitivity | Specificity | PPV | NPV | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n/N | (%) | 95% CI | n/N | (%) | 95% CI | (%) | 95% CI | (%) | 95% CI | |
| Smear microscopy vs RSa | 29/157 | (18.5) | 12.9–25.6 | 12/12 | (100) | 71.6–100 | 100 | 85.4–100 | 9.2 | 5–15 |
| Culture vs RS | 99/157 | (63) | 55–70.5 | 13/13 | (100) | 71.7–100 | 100 | 95.3–100 | 18.31 | 10.5–29.6 |
| RD qPCR vs RS | 157/157 | (100) | 97–100 | 12/13 | (92.3) | 62.1–99.6 | 99.4 | 96–100 | 100 | 69.9–100 |
| RD qPCR vs Culture | 99/99 | (100) | 95.3–100 | 12/71 | (16.9) | 9.4–28.1 | 62.7 | 54.6–70.1 | 100 | 69.9–100 |
aRS: reference standard for EPTB is defined as positive culture and/or at least two positive CRS* criteria; *CRS: Composite reference standard: (i) TB clinical symptoms, (ii) histology/cytology findings, (iii) radiological tests, (iv) therapeutic response to anti-TB treatment (ATT); PPV: positive predictive Value; NPV: Negative Predictive Value; n: index group; N: control group; CI: confidence interval