Table 3.
Diagnostic performance of index tests, stratified for high risk and baseline risk pregnancies
| Fetal anomaly | TP | FP | TN | FN | FPR Pr (FP|N) | SPEC Pr (−|N) | SENS Pr (+|A) | PPV Pr (A|+) | NPV Pr (N|−) | ACC Pr (TP+TN|all) |
|---|---|---|---|---|---|---|---|---|---|---|
| n | n | n | n | n, % (95% CI) | n, % (95% CI) | n, % (95% CI) | n, % (95% CI) | n, % (95% CI) | n, % (95% CI) | |
| High-risk pregnancies | ||||||||||
| Proton™ | ||||||||||
| T21 | 145 | 4 | 1707 | 2 | 4/1711 | 1707/1711 | 145/147 | 145/149 | 1707/1709 | 1852/1858 |
| 0.23 (0.06–0.60) | 99.7 (99–100) | 98.6 (95–100) | 97.3 (93–100) | 99.8 (99–100) | 99.6 (99–100) | |||||
| T18 | 48 | 5 | 1805 | 0 | 5/1810 | 1805/1810 | 48/48 | 48/53 | 1805/1805 | 1853/1858 |
| 0.28 (0.09–0.64) | 99.7 (99–100) | 100 (92–100) | 90.5 (79–97) | 100 (99–100) | 99.7 (99–100) | |||||
| T13 | 6 | 6 | 1846 | 0 | 6/1852 | 1846/1852 | 6/6 | 6/12 | 1846/1846 | 1852/1858 |
| 0.32 (0.12–0.70) | 99.6 (99–100) | 100 (54–100) | 50.0 (21–79) | 100 (99–100) | 99.6 (99–100) | |||||
| Turner | 17 | 17 | 1821 | 3 | 17/1838 | 1821/1838 | 17/20 | 17/34 | 1821/1824 | 1838/1858 |
| 0.92 (0.54–2) | 99.0 (98–100) | 85.0 (62–97) | 50.0 (32–68) | 99.8 (99–100) | 98.9 (98–100) | |||||
| T13, T18, or T21 | 199 | 15 | 1642 | 2 | 15/1657 | 1642/1657 | 199/201 | 199/214 | 1642/1644 | 1841/1858 |
| 0.91 (0.51–2) | 99.0 (98–100) | 99.0 (96–100) | 92.9 (88–97) | 99.8 (99–100) | 99.0 (98–100) | |||||
| HiSeq™ | ||||||||||
| T21 | 146 | 7 | 1714 | 1 | 7/1721 | 1714/1721 | 146/147 | 146/153 | 1714/1715 | 1860/1868 |
| 0.41 (0.16–0.84) | 99.5 (99–100) | 99.3 (96–100) | 95.4 (90–99) | 99.9 (99–100) | 99.5 (99–100) | |||||
| T18 | 49 | 5 | 1814 | 0 | 5/1819 | 1814/1819 | 49/49 | 49/54 | 1814/1814 | 1863/1868 |
| 0.27 (0.09–0.64) | 99.7 (99–100) | 100 (92–100) | 90.7 (79–97) | 100 (99–100) | 99.7 (99–100) | |||||
| T13 | 7 | 3 | 1858 | 0 | 3/1861 | 1858/1861 | 7/7 | 7/10 | 1858/1858 | 1865/1868 |
| 0.16 (0.03–0.47) | 99.8 (99–100) | 100 (59–100) | 70.0 (34–94) | 100 (99–100) | 99.8 (99–100) | |||||
| Turner | 14 | 6 | 1842 | 6 | 6/1848 | 1842/1848 | 14/20 | 14/20 | 1842/1848 | 1856/1868 |
| 0.32 (0.12–0.71) | 99.6 (99–100) | 70.0 (45–89) | 70.0 (45–89) | 99.6 (99–100) | 99.3 (98–100) | |||||
| T13, T18, or T21 | 202 | 15 | 1650 | 1 | 15/1665 | 1650/1665 | 202/203 | 202/217 | 1650/1651 | 1852/1868 |
| 0.90 (0.51–2) | 99.0 (98–100) | 99.5 (97–100) | 93.0 (88–97) | 99.9 (99–100) | 99.1 (98–100) | |||||
| Baseline risk pregnancies | ||||||||||
| Proton™ | ||||||||||
| T21 | 5 | 3 | 1558 | 0 | 3/1561 | 1558/1561 | — | — | — | — |
| 0.19 (0.04–0.56) | 99.8 (99–100) | — | — | — | — | |||||
| T18 | 0 | 3 | 1563 | 0 | 3/1566 | 1563/1566 | — | — | — | — |
| 0.19 (0.04–0.56) | 99.8 (99–100) | — | — | — | — | |||||
| T13 | 0 | 4 | 1562 | 0 | 4/1566 | 1562/1566 | — | — | — | — |
| 0.26 (0.07–0.65) | 99.7 (99–100) | — | — | — | — | |||||
| Turner | 1 | 11 | 1554 | 0 | 11/1565 | 1554/1565 | — | — | — | — |
| 0.70 (0.35–2) | 99.2 (98–100) | — | — | — | — | |||||
| T13, T18 or T21 | 5 | 10 | 1551 | 0 | 10/1561 | 1551/1561 | — | — | — | — |
| 0.64 (0.31–2) | 99.3 (98–100) | — | — | — | — | |||||
| HiSeq™ | ||||||||||
| T21 | 5 | 0 | 1581 | 0 | 0/1581 | 1581/1581 | — | — | — | — |
| 0 (0–0.23) | 100 (99–100) | — | — | — | — | |||||
| T18 | 0 | 3 | 1583 | 0 | 3/1586 | 1583/1586 | — | — | — | — |
| 0.19 (0.04–0.55) | 99.8 (99–100) | — | — | — | — | |||||
| T13 | 0 | 4 | 1582 | 0 | 4/1586 | 1582/1586 | — | — | — | — |
| 0.25 (0.07–0.64) | 99.7 (99–100) | — | — | — | — | |||||
| Turner | 1 | 6 | 1579 | 0 | 6/1585 | 1579/1585 | — | — | — | — |
| 0.38 (0.14–0.82) | 99.6 (99–100) | — | — | — | — | |||||
| T13, T18, or T21 | 5 | 7 | 1574 | 0 | 7/1581 | 1574/1581 | — | — | — | — |
| 0.44 (0.18–0.91) | 99.5 (99–100) | — | — | — | — | |||||
Diagnostic performance of the two index tests (Proton™ NIPS and HiSeq™ NIPS) for T21, T18, T13; Turner syndrome and the detection of any of T13, T18, or T21 (rows) in high-risk pregnancies (top half) and baseline risk pregnancies (bottom half). The first four data columns represent the 2 × 2 table absolute frequencies observed as true positives (TP), false positives (FP), true negatives (TN), and false negative (FN), followed, for high-risk pregnancies, with the false positive rate (FPR), the clinical sensitivity (SENS), the clinical specificity (SPEC), the positive predictive value (PPV), the negative predictive value (NPV), and the clinical accuracy (ACC) while, for baseline risk pregnancies, only are shown the false positive rate (FPR) and the clinical specificity (SPEC). For each ratio, the corresponding table box contains the absolute ratio (n), the relative ratio (%), and the 95% confidence interval of the relative ratio (95% CI)