Table 7 Performance of two screening tests with new contingent screening strategy
From: A new contingent screening strategy increased detection rate of trisomy 21 in the first trimester
Risk stratification | Serum biochemical screening | Combined first-trimester screening | ||||
|---|---|---|---|---|---|---|
n(%) | Trisomy 21 (%) | OAPR | n(%) | Trisomy 21 (%) | OAPR | |
high risk (risk ≥ 1/270) | 1,874 (5.31%) | 29 (61.70%) | 1:64 | 875 (2.50%) | 34 (72.34%) | 1:26 |
intermediate risk (1/1,000 ≤ risk < 1/270) | 5,029 (14.24%) | 9 (19.15%) | 1:558 | 1,748 (4.99%) | 6 (12.77%) | 1:291 |
free β-hCG MoM ≥ 2.75 PAPP-A MoM ≤ 0.5 (risk < 1/1,000) | 2,194 (6.21%) | 5 (10.64%) | 1:439 | 4,005 (11.43%) | 6 (12.77%) | 1:668 |
free β-hCG MoM < 2.75 PAPP-A MoM > 0.5 (risk < 1/1,000) | 26,211 (74.24%) | 4 (8.51%) | 28,398 (81.08%) | 1 (2.13%) | ||