Table 4.
Performance of the model in cohort I and cohort II.
| Cut-off valuea | ≥3 | ≥4 | ≥5 | ≥6 | ≥7 |
|---|---|---|---|---|---|
| Cohort I | |||||
| Sensitivity | 93% (76–99) | 79% (60–91) | 45% (27–64) | 28% (13–47) | 17% (7–36) |
| Specificity | 86% (74–94) | 88% (76–95) | 92% (81–96) | 98% (88–99) | 100% (91–100) |
| PPV | 79% (62–91) | 79% (60–91) | 76% (50–92) | 89% (59–99) | 100% (46–100) |
| NPV | 96% (84–99) | 88% (76–95) | 75% (62–85) | 71% (59–81) | 68% (57–78) |
| Cohort II | |||||
| Sensitivity | 75% (47–92) | 69% (41–88) | 63% (36–84) | 56% (31–79) | 44% (21–69) |
| Specificity | 94% (68–100) | 94% (68–100) | 100% (76–100) | 100% (76–100) | 100% (76–100) |
| PPV | 92% (62–100) | 92% (60–100) | 100% (66–100) | 100% (63–100) | 100% (56–100) |
| NPV | 79% (54–93) | 75% (51–90) | 73% (50–88) | 70% (47–86) | 64% (43–81) |
PPV positive predictive value, NPV negative predictive value.
aA cut-off value of ≥3 means that an ultrasound score of 3 or more is defined as abnormal.