Table 3 The accuracy of fetal fibronectin tests
fFN | Sensitivity | Specificity | PPV | NPV | p value |
|---|---|---|---|---|---|
Preterm delivery < 37w | |||||
> 10ng/ml | 0.80 | 0.68 | 0.40 | 0.93 | 0.0060 |
> 50 ng/ml | 0.60 | 0.87 | 0.55 | 0.89 | 0.0020 |
> 100 ng/ml | 0.40 | 0.95 | 0.67 | 0.86 | 0.0030 |
> 200 ng/ml | 0.40 | 1.00 | 1.00 | 0.86 | 0.0001 |
> 500 ng/ml | 0.20 | 1.00 | 1.00 | 0.83 | 0.0050 |
Preterm delivery < 34w | |||||
> 10ng/ml | 1.00 | 0.67 | 0.30 | 1.00 | 0.0020 |
> 50 ng/ml | 1.00 | 0.88 | 0.55 | 1.00 | 0.0001 |
> 100 ng/ml | 0.67 | 0.95 | 0.67 | 0.95 | 0.0001 |
> 200 ng/ml | 0.67 | 1.00 | 1.00 | 0.95 | 0.0001 |
> 500 ng/ml | 0.33 | 1.00 | 1.00 | 0.91 | 0.0001 |
Delivery within 48 h | |||||
> 10ng/ml | 1.00 | 0.56 | 0.25 | 1.00 | 0.0010 |
> 50 ng/ml | 0.80 | 0.84 | 0.36 | 0.97 | 0.0010 |
> 100 ng/ml | 0.80 | 0.95 | 0.67 | 0.98 | 0.0001 |
> 200 ng/ml | 0.80 | 1.00 | 1.00 | 0.98 | 0.0001 |
> 500 ng/ml | 0.40 | 1.00 | 1.00 | 0.93 | 0.0001 |
Delivery within 7 days | |||||
> 10ng/ml | 1.00 | 0.68 | 0.35 | 1.00 | 0.0010 |
> 50 ng/ml | 0.86 | 0.88 | 0.55 | 0.97 | 0.0001 |
> 100 ng/ml | 0.57 | 0.95 | 0.67 | 0.93 | 0.0001 |
> 200 ng/ml | 0.57 | 1.00 | 1.00 | 0.93 | 0.0001 |
> 500 ng/ml | 0.29 | 1.00 | 1.00 | 0.89 | 0.0001 |
Delivery within 14 days | |||||
> 10ng/ml | 1.00 | 0.68 | 0.35 | 1.00 | 0.0010 |
> 50 ng/ml | 0.86 | 0.88 | 0.55 | 0.97 | 0.0001 |
> 100 ng/ml | 0.57 | 0.95 | 0.67 | 0.93 | 0.0001 |
> 200 ng/ml | 0.57 | 1.00 | 1.00 | 0.93 | 0.0001 |
> 500 ng/ml | 0.29 | 1.00 | 1.00 | 0.89 | 0.0001 |
PPV: positive predictive value; NPV: negative predictive value | |||||