Table 4 Receiver operating characteristic analyses for prediction of massive hemorrhage based on cervical length and cervical area
Variable | Cut-off | Sensitivity % (95% CI) | Specificity % (95% CI) | PPV % | NVP % | Pa |
|---|---|---|---|---|---|---|
Cervical length (mm) | 28 | 80.551 (73.895–86.806) | 88.253 (81.952–94.239) | 85.484 | 84.086 | 0.001 |
Cervical length (mm) | 30 | 83.605 (77.283–88.626) | 86.328 (80.247–92.038) | 84.297 | 86.018 | 0.001 |
Cervical length (mm) | 32 | 85.450 (78.028–89.509) | 83.159 (78.382–90.426) | 81.335 | 86.936 | 0.001 |
Cervical area (cm2) | 3.5 | 83.214 (78.024–89.482) | 87.322 (81.206–92.519) | 84.933 | 85.830 | 0.001 |
Cervical area (cm2) | 4.0 | 85.035 (79.254–88.329) | 84.254 (78.291–89.038) | 82.263 | 86.765 | 0.001 |
Cervical area (cm2) | 4.5 | 86.958 (81.219–91.560) | 82.359 (77.084–86.690) | 80.892 | 88.028 | 0.001 |