Table 3.
Positive predictive value (PPV) and negative predictive value (NPV) in the study cohorta
| Diagnostic system | 52% prevalence | 5% prevalence | 10% prevalence | 15% prevalence | ||||
|---|---|---|---|---|---|---|---|---|
| PPV (%) | NPV (%) | PPV (%) | NPV (%) | PPV (%) | NPV (%) | PPV (%) | NPV (%) | |
| KJ with | 82.2 | 70.3 | 18.3 | 98.0 | 32.1 | 95.9 | 42.9 | 93.6 |
| KJ without | 65.8 | 51.9 | 8.6 | 95.7 | 16.5 | 91.3 | 23.8 | 86.9 |
| Tidjani with | 92.7 | 83.3 | 38.4 | 99.0 | 56.8 | 98.0 | 67.6 | 96.8 |
| Tidjani without | 87.5 | 61.1 | 25.4 | 97.0 | 41.8 | 93.9 | 53.3 | 90.6 |
| MoH 30 points | 60.2 | 70.7 | 6.9 | 98.0 | 13.4 | 95.9 | 19.8 | 93.7 |
| MoH 40 points | 69.0 | 57.7 | 9.7 | 96.6 | 18.5 | 93.0 | 26.7 | 89.3 |
| BM with | 59.1 | 81.6 | 6.6 | 98.9 | 12.9 | 97.5 | 19.1 | 96.5 |
| BM without | 56.5 | 63.8 | 5.9 | 97.3 | 11.8 | 94.5 | 17.5 | 91.5 |
KJ, Kenneth Jones; MoH, Brazilian Ministry of Health; BM, Ben Marais.
a
Calculations for each were made considering (with) or not considering (without) microbiological data. For the MoH system, values were calculated considering a 30-point or 40-point TB case cut-off. The PPV and NPV of each system was calculated using the prevalence in the study cohort (52%), as well as prevalence rates commonly observed at healthcare units (5%, 10%, 15%).