The diagnostic values of non-treponemal titres before treatment for CS stratified by two treatment groups
| Subgroup | AUC (95% CI) | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | Youden’s index |
| Untreated during pregnancy | 0.80 (0.72 to 0.88) | 81.5 (66.8 to 96.1) | 78.5 (72.3 to 84.6) | 37.3 (24.9 to 49.6) | 96.4 (93.4 to 99.5) | 0.60 |
| Treated during pregnancy | 0.73 (0.59 to 0.87) | 66.7 (40.0 to 93.3) | 78.8 (76.6 to 81.0) | 2.7 (0.9 to 4.6) | 99.6 (99.3 to 100.0) | 0.45 |
AUC, area under the curve; CS, congenital syphilis; NPV, negative predicted value; PPV, positive predicted value.