TABLE 3.
Simple proportion and weighted proportion scores per assay calculated for rifampicin and isoniazida
| Assay | Rifampicin Sp (%)b (no. of mutations detected/total no. of mutations tested) | Rifampicin Sw (%)c | Isoniazid Sp (%)b (no. of mutations detected/total no. of mutations tested) | Isoniazid Sw (%)c |
|---|---|---|---|---|
| Genotype MTBDRplus | 95 (19/20) | 99 | 100 (22/22) | 100 |
| Abbott RealTime MTB RIF/INH | 80 (48/60) | 94 | 100 (66/66) | 100 |
| BD Max MDR-TB | 100 (60/60) | 100 | 95 (63/66) | 96 |
| Hain FluoroType MTBDR | 97 (58/60) | 99 | 96 (63/66) | 96 |
| Roche cobas MTB-RIF/INH | 90 (54/60) | 99 | 98 (65/66) | NA |
a
NA, not applicable (could not be calculated as the assay does not discriminate between inhA promoter and katG mutations).
b
Sensitivity was expressed as a simple proportion (Sp), representing the overall number of mutations detected as a fraction of the total number of mutations tested in this study.
c
The frequency-weighted sensitivity (Sw) indicates the number of mutations correctly detected in this study weighted by the estimated frequency with which the specific mutation occurs globally (WHO drug resistance surveillance data).