Table 4.
Positive predictive value (PPV) and negative predictive value (NPV), with 95% uncertainty intervals (UIs), for example scenarios of 10%, 20% and 30% pre-test probability. “Probability best” = the proportion of Monte Carlo simulations in which the test had the highest PPV or NPV. Specificity was estimated from 1,995 pre-pandemic samples (Table 1) and sensitivity from 354 Roche Elecsys® positives with unknown previous infection status at clinic visit (Table 3).
| AbC-19TM | Orient Gene 1 band | Orient Gene 2 bands | SureScreen 1 band | SureScreen 2 bands | Biomerica 1 band | Biomerica 2 bands | |
| Positive predictive value (PPV) | |||||||
| PPV at 10% pre-test probability (95% UI) | 81.7% (77.1, 85.6) | 77.0% (72.6, 80.8) |
70.9% (66.7, 74.8) |
89.6% (84.7, 93.0) |
76.8% (72.1, 81.0) |
79.3% (74.2, 83.6) |
56.1% (52.1, 59.9) |
| PPV at 20% pre-test probability (95% UI) | 91.0% (88.3, 93.0) |
88.3% (85.6, 90.5) |
84.6% (81.8, 87.0) |
95.1% (92.6, 96.8) |
88.2% (85.3, 90.5) |
89.6% (86.6, 92.0) |
74.2% (71.0, 77.1) |
| PPV at 30% pre-test probability (95% UI) | 94.5% (92.8, 95.8) |
92.8% (91.1, 94.2) |
90.4% (88.5, 92.0) |
97.1% (95.5, 98.1) |
92.8% (90.9, 94.3) |
93.7% (91.7, 95.2) |
83.1% (80.7, 85.2) |
| Ranked PPV (UI) | 2 (2, 4) | 4 (2, 5) | 6 (6, 6) | 1 (1, 1) | 4 (2, 5) | 3 (2, 5) | 7 (7, 7) |
| Probability best PPV | 0.01 | 0.00 | 0.00 | 0.99 | 0.00 | 0.00 | 0.00 |
| Negative predictive value (NPV) | |||||||
| NPV at 10% pre-test probability (95% UI) | 98.3% (97.9, 98.7) |
99.1% (98.7, 99.4) |
99.1% (98.8, 99.4) |
98.4% (98.0, 98.8) |
98.8% (98.4, 99.2) |
99.1% (98.7, 99.4) |
99.1% (98.7, 99.3) |
| NPV at 20% pre-test probability (95% UI) | 96.3% (95.3, 97.0) |
98.0% (97.2, 98.6) |
98.0% (97.2, 98.6) |
96.5% (95.5, 97.3) |
97.4% (96.6, 98.1) |
97.9% (97.1, 98.6) |
97.9% (97.0, 98.5) |
| NPV at 30% pre-test probability (95% UI) | 93.7% (92.2, 95.0) |
96.6% (95.3, 97.6) |
96.7% (95.4, 97.7) |
94.1% (92.6, 95.4) |
95.7% (94.3, 96.8) |
96.5% (95.1, 97.5) |
96.4% (95.0, 97.5) |
| Ranked NPV (UI) | 7 (6, 7) | 2 (1, 4) | 2 (1, 4) | 6 (6, 7) | 5 (3, 5) | 3 (1, 5) | 3 (1, 5) |
| Probability best NPV | 0.00 | 0.13 | 0.48 | 0.00 | 0.00 | 0.29 | 0.10 |