Variables

Cervical Length < 25 mm

PremaQuick

P value

Sensitivity

59/(59 + 49) × 100 = 54.6%

43/(43 + 65) × 100 = 39.8%

0.15

Specificity

63/(63 + 49) × 100 = 56.3%

107/(107 + 5) × 100 = 95.5%

0.02*

PPV

59/(59 + 49) × 100 = 54.6%

43/(43 + 5) × 100 = 89.6%

0.03*

NPV

63/(63 + 49) × 100 = 56.3%

107/(107 + 65) × 100 = 62.2%

0.7

Accuracy

59 + 63/(59 + 63 + 49 + 49) × 100 = 55.5%

43 + 107/(43 + 107 + 5 + 65) × 100 = 68.2%

0.4