TABLE 2.
Sensitivity and specificity of the QIAplex TB assay in comparison to phenotypic antimycobacterial susceptibility resultsa
| Antimycobacterial drug(s) | No. of isolates with result (standardb/ QIAplex):
|
Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | |||
|---|---|---|---|---|---|---|---|---|
| R/R | R/S | S/R | S/S | |||||
| INH | 35 | 6 | 6 | 149 | 85.4 | 96.1 | 85.4 | 96.1 |
| RIF | 17 | 1 | 1 | 177 | 94.5 | 99.4 | 94.7 | 99.4 |
| STM | 48 | 21 | 1 | 126 | 69.6 | 99.2 | 98.6 | 85.8 |
| EMB | 3 | 3 | 2 | 188 | 50.0 | 98.9 | 60.0 | 98.4 |
| INH + RIF (MDR-TB) | 13 | 2 | 0 | 181 | 86.7 | 100.0 | 98.9 | 100.0 |
a
PPV, positive predictive value; NPV, negative predictive value; R, resistant; S, susceptible.
b
Phenotypic susceptibility profiles determined by the absolute-concentration method.