Table 2 Performance of reflex DNA screening using a 1 in 800 combined test risk cutoff to select women for a DNA test compared with women only receiving the combined test using a 1 in 150 risk cutoff
From: Prenatal reflex DNA screening for trisomies 21, 18, and 13
Screening method | Affected | Unaffected a | ||||
|---|---|---|---|---|---|---|
Trisomy | Positive/total | DR (95% CI) | Positive/total | FPR (95% CI) | OAPR | |
Reflex DNA screening | 21 | 69/73 | 95% (87–98%) | 4/22,706 | 0.02% (0.00–0.05%) | 17:1 |
18 | 24/25 | 96% (80–100%) | 0/22,706 | 0.00% (0.00–0.02%) | >24:1 | |
13 | 8/8 | 100% (63–100%) | 0/22,706 | 0.00% (0.00–0.02%) | >8:1 | |
All | 101/106 | 95% (89–98%) | 4/22,706 | 0.02% (0.00–0.05%) | 25:1 | |
Combined test only | 21 | 59/73 | 81% (70–89%) | 532/22,706 | 2.34% (2.15–2.55%) | 1:9 |
18 | 20/25 | 80% (59–93%) | 10/22,706 | 0.05% (0.02–0.08%) | 1:2 | |
13 | 6/8 | 75% (35–97%) | 55/22,706 | 0.24% (0.18–0.32%) | 1:9 | |
All | 86/106 | 81% (72–88%) | 549/22,706 | 2.42% (2.22–2.62%) | 1:6 | |
