Table 2 Screening performance for trisomy 21 using contingent, reflex, and primary cfDNA screening strategies (assuming a screening population of 100,000 women, and eFTS used as the primary screening test for contingent and reflex cfDNA screening)

# eFTS positive

11,250

11,250

11,250

11,250 (a)

–

–

# cfDNA screening

11,250

11,250

11,250

9850

100,000

100,000

# cfDNA screening high risk

253 (b)

247 (c)

254 (c)

82 (c)

354 (b)

356 (c)

# cfDNA screening no-call result

135 (d)

371 (e)

56 (e)

49 (e)

1200 (d)

500 (e)

# patient receiving GC

11,250 (f)

618 (g)

311 (g)

1532 (h)

1554 (g)

856 (g)

# GC session

11,443 (i)

618 (g)

311 (g)

1532 (h)

1554 (g)

856 (g)

# PND (cfDNA screening high risk)

253

247

254

1482 (j)

354

356

# PND (cfDNA screening high risk/no-call)

388

618

311

1532

1554

856

# Expected T21

260

260

260

260

260

260

# T21 diagnosed through PND (cfDNA screening high risk)

242

236

243

246 (k)

254

256

# T21 diagnosed through PND (cfDNA screening high risk/no-call)

245

245

245

246

257

257

# T21 eFTS negative

13

13

13

13

–

–

# T21 cfDNA screening low risk

2

2

2

1

3

3

# T21 cfDNA screening no-call

3

8

1

0

3

1

# T21 missed by eFTS or cfDNA screening

15

15

15

14

3

3

# T21 livebirth

9

9

9

8

2

2

# Procedure related fetal loss

0

1

0

4

4

2

DR (cfDNA screening high risk)

92.2%

91.0%

93.6%

94.6%

97.7%

98.5%

FPR (cfDNA screening high risk)

0.01%

0.01%

0.01%

1.24%

0.10%

0.10%

Overall DR (all cfDNA screening no-call have a PND)

94.1%

94.1%

94.1%

94.7%

99.0%

99.0%

Overall FPR (all cfDNA screening no-call have a PND)

0.14%

0.37%

0.07%

1.29%

1.30%

0.60%