Table 4. Operating characteristics of molecular tests in chronic phase of Chagas disease including only negatives without risk factors.
| Operating characteristics | Chronic phase N = (481/510) | |
|---|---|---|
| qPCR (95% CI) | cPCR (95% CI) | |
| Sensitivity | 64.2 (59.9–58.4) | 56.8 (52.3–61.1) |
| Specificity | 100.0 (88.3–100.0) | 100 (88.3–100.0) |
| PPV | 100.0 (98.8–100.0) | 100.0 (98.6–100.0) |
| NPV | 14.4 (10.2–19.9) | 12.2 (8.7–17.0) |
| DP | 66.3(62.1–70.2) | 59.2 (54.9–63.4) |
| LR+ | Undefined | |
| LR- | 0.36 (0.35–0.36) | 0.43 (0.42–0.44) |
| Kappa index | 0.17(0.1213–0.218) | 0.13 (0.09–0.17) |
PPV: Positive predictive value; NPV: Negative predictive value; DP: diagnostic precision; LR+: positive likelihood ratio; LR-: negative likelihood ratio. When the specificity is 100% the positive likelihood ratio is undefined. N = (Positive gold standard/ total assayed)