Table 5 Simulation of positive and negative predictive values according to different TB prevalence rates
Simulated prevalence rates | N = 294 | ||
|---|---|---|---|
TB N = 55 | NTB N = 239 | ||
PPV (%) | NPV (%) | ||
4.9% | Smear plus culture | 50 | 99 |
Smear plus Detect-TB | 48 | 99 | |
PPV (%) | NPV (%) | ||
10% | Smear plus culture | 68 | 99 |
Smear plus Detect-TB | 66 | 98 | |
PPV (%) | NPV (%) | ||
20% | Smear plus culture | 82 | 99 |
Smear plus Detect-TB | 81 | 97 | |
PPV (%) | NPV (%) | ||
30% | Smear plus culture | 89 | 98 |
Smear plus Detect-TB | 88 | 94 | |
PPV (%) | NPV (%) | ||
40% | Smear plus culture | 92 | 97 |
Smear plus Detect-TB | 92 | 92 | |
PPV (%) | NPV (%) | ||
60% | Smear plus culture | 96 | 94 |
Smear plus Detect-TB | 96 | 83 | |