Table 2.
Results of Romed COVID-19 antigen test compared to RT-qPCR on 900 throat nasopharyngeal samples
| Patients | Emergency room patients | Nursing home residents | Health care workers | All patients |
|---|---|---|---|---|
| RT-qPCR-negative samples | 150 | 225 | 225 | 600 |
| RT-qPCR-positive samples | 150 | 75 | 75 | 300 |
| Specificity (95% CI) | 100 (96.9–100) | 100 (97.9–100) | 99.6 (97.2–100) | 99.8 (98.9–100) |
| Sensitivity (95% CI) | ||||
| Overall | 65.3 (57.1–72.8) | 76.0 (64.5–84.8) | 86.7 (76.4–93.1) | 73.3 (67.9–78.2) |
| CT < 30 | 90.6 (82.9–95.1) | 85.1 (73.8–92.2) | 92.6 (83.0–97.3) | 89.6 (84.9–93.0) |
| CT < 20 | 100 (84.0–100) | 100 (82.2–100) | 100 (79.1–100) | 100 (99.3–100) |
| PPV (95% CI) | ||||
| Prevalence 1% | 100 (N.A.) | 100 (N.A.) | 66.3 (22.8–93.3) | 81.6 (38.5–96.9) |
| Prevalence 10% | 100 (N.A.) | 100 (N.A.) | 95.6 (75.4–99.4) | 98.0 (87.3–99.7) |
| Prevalence 25% | 100 (N.A.) | 100 (N.A.) | 98.5 (90.2–99.8) | 99.3 (95.4–99.9) |
| Prevalence 50% | 100 (N.A.) | 100 (N.A.) | 99.5 (96.5–99.9) | 99.8 (98.4–100) |
| NPV (95% CI) | ||||
| Prevalence 1% | 99.7 (99.6–99.7) | 99.8 (99.6–99.8) | 99.9 (99.8–99.9) | 99.7 (99.7–99.9) |
| Prevalence 10% | 96.3 (95.4–97.0) | 97.4 (96.2–98.3) | 98.5 (97.4–99.2) | 97.1 (96.5–97.6) |
| Prevalence 25% | 89.6 (87.4–91.5) | 92.6 (89.3–94.9) | 95.7 (92.6–97.6) | 91.8 (90.3–93.1) |
| Prevalence 50% | 74.3 (69.8–78.2) | 80.7 (73.6–86.2) | 88.2 (89.6–95.7) | 78.9 (75.6–81.9) |
Specificity, sensitivity, PPV, and NPV are reported with 95% CI. The PPV was calculated for 4 scenarios: 1% and 10% prevalence in a general population and 25 and 50% prevalence in a high-risk population
CI confidence interval, CT cycle threshold, N.A. not applicable