Table 5 Sensitivity and specificity of conventional methods, nMPCR assay and CRS with respect to different specimens
Different testes | Test results | TB group | Control (n = 150) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | CI |
|---|---|---|---|---|---|---|---|---|
Pulmonary TB (n = 535) | ||||||||
AFB smear | Positive Negative | 287 128 | 0 120 | 69.2 | 100 | 100 | 48.4 | 64.5 % – 73.6 % |
Culture | Positive Negative | 329 86 | 0 120 | 79.3 | 100 | 100 | 58.2 | 75.0 % – 83.1 % |
Single step mPCR | Positive Negative | 345 70 | 0 120 | 83.1 | 100 | 100 | 63.2 | 79.2 % – 86.6 % |
nMPCR | Positive Negative | 403 12 | 0 120 | 97.1 | 100 | 100 | 90.9 | 95.0 % – 98.5 % |
CRS | Positive Negative | 415 0 | 0 120 | 100 | 100 | 100 | 100 | 99.1 % –100.0 % |
Extra-pulmonary TB (n = 65) | ||||||||
Z-N smear | Positive Negative | 15 20 | - 30 | 42.9 | 100 | 100 | 60.0 | 26.3 % – 60.6 % |
Culture | Positive Negative | 19 16 | - 30 | 54.3 | 100 | 100 | 65.2 | 36.6 % – 71.2 % |
Single step mPCR | Positive Negative | 20 15 | - 30 | 57.1 | 100 | 100 | 66.7 | 39.3 % – 73.7 % |
nMPCR | Positive Negative | 32 3 | 2 28 | 91.4 | 93.3 | 94.1 | 90.3 | 76.9 % – 98.2 % |
CRS | Positive Negative | 35 0 | 0 30 | 100 | 100 | 100 | 100 | 90.0 % to 100.0 % |