Table 2 Screening performance for T21 by maternal age in FTSS and NIPT groups.

TP

15

13

2

5

3

2

FP

1634

1578

56

4

3

1

TN

21,484

21,243

241

10,413

6769

3644

FN

3

3

0

1

1

0

Number screened

23,136

22,837

299

10,423

6776

3647

Sensitivity

(95%CI)

83.33% (58.58–96.42%)

81.25% (54.35–95.95%)

100.00% (15.81–100.00%)

83.33% (35.88–99.58%)

75.00% (19.41–99.37%)

100.00% (15.81–100.00%)

Specificity

(95%CI)

92.93% (92.59–93.26%)

93.09% (92.75–93.41%)

81.27% (76.35–85.59%)

99.96% (99.90–99.99%)

99.96% (99.87–99.99%)

99.97% (99.85–100.00%)

PPV

(95%CI)

0.91% (0.51–1.50%)

0.82% (0.44–1.39%)

3.45% (0.42–11.90%)

55.56% (21.20–86.30%)

50.00% (11.81–88.19%)

66.67% (9.43–99.16%)

FPR

(95%CI)

7.07% (6.74–7.41%)

6.91% (6.59–7.25%)

18.73% (14.41–23.60%)

0.04% (0.01–0.10%)

0.04% (0.01–0.13%)

0.03% (0.00–0.15%)

FNR

(95%CI)

16.67% (3.58–41.42%)

18.75% (4.05–45.65%)

0.00% (0.00–84.19%)

16.67% (0.42–64.12%)

25.00% (0.63–80.59%)

0.00% (0.00–84.19%)