TABLE 3.
Performance evaluation of GeneChip for multidrug-resistant and susceptible tuberculosis cases with different treatment historiesa
| GeneChip | No. of cases by conventional drug susceptibility testingc |
Sensitivity (%) |
Specificity (%) |
AR | PPV (%) | NPV (%) | Kappa | PLR (%) | NLR (%) | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| MDR-TB (%) | Non-MDR (%) | Total | |||||||||
| New cases | 81.8 | 99.0b | 98.4b | 76.6 | 99.3b | 0.78 | 84.0 | 0.18 | |||
| MDR-TB | 36 (81.8) | 11 (1.0) | 47 | ||||||||
| Non-MDR | 8 (18.2) | 1,118 (99.0) | 1,126 | ||||||||
| Total | 44 | 1,129 | |||||||||
| Previously treated cases | 77.8 | 93.4 | 90.3 | 74.5 | 94.4 | 0.70 | 11.8 | 0.24 | |||
| MDR-TB | 35 (77.8) | 12 (6.6) | 47 | ||||||||
| Non-MDR | 10 (22.2) | 170 (93.4) | 180 | ||||||||
| Total | 45 | 182 | |||||||||
| All cases | 79.8 | 98.3 | 97.1 | 75.5 | 98.6 | 0.76 | 45.5 | 0.21 | |||
| MDR-TB | 71 (79.8) | 23 (1.8) | 94 | ||||||||
| Non-MDR | 18 (20.2) | 1,288 (98.2) | 1,306 | ||||||||
| Total | 89 | 1,311 | |||||||||
a
Abbreviations: TB, tuberculosis; MDR, multidrug resistant; PPV, positive predictive value; NPV, negative predictive value; AR, agreement rate; PLR, positive likelihood ratio; NLR, negative likelihood ratio.
b
Statistically significant (P < 0.05).
c
Culture was used as the gold standard.