| Sn (%) | Sp (%) | PPV (%) | NPV (%) | LR+ | LR- |
Bishop ≥ 7 | 70.41 | 79.11 | 67.65 | 81.17 | 3.74 | 0.36 |
Cervical obliteration ≥ 50% | 85.71 | 16.46 | 38.89 | 65.00 | 1.02 | 0.87 |
Cervical dilatation ≥ 2 cm | 59.18 | 74.68 | 59.18 | 74.68 | 2.34 | 0.55 |
Ultrasound cervical length < 25 mm | 87.76 | 33.54 | 45.03 | 81.54 | 1.32 | 0.36 |
Sacculation | 69.39 | 82.91 | 71.58 | 81.37 | 4.06 | 0.34 |