Table 2.
Sensitivity of each immunoassay categorised by days of symptoms
| Days of symptoms |
Overall AUC [95% CI] | ||||
|---|---|---|---|---|---|
| 1–6 (n = 80) | 7–13a (n = 37) | 14–20 (n = 26) | 21–64 (n = 30) | ||
| Abbott | |||||
| n (%) | 7 (8.8) | 15 (40.5) | 22 (84.6) | 25 (83.3) | |
| 95% CI | 3.6–17.2 | 24.8–57.9 | 65.1–95.6 | 65.3–94.4 | |
| AUC [95% CI] | 0.533 [0.451–0.614]p = 0.420 | 0.700 [0.586–0.814]p < 0.001 | 0.917 [0.828–1.0]p < 0.001 | 0.914 [0.832–0.998]p < 0.001 | 0.692 [0.634–0.751]p < 0.001 |
| Beckmanb | |||||
| n (%) | 8 (10.0) | 11 (29.7) | 20 (76.9) | 26 (86.7) | |
| 95% CI | 4.4–18.8 | 15.9–47.0 | 56.3–91.0 | 69.3–96.2 | |
| AUC [95% CI] | 0.549 [0.467–0.632]p = 0.220 | 0.654 [0.549–0.769]p = 0.005 | 0.913 [0.824–1.0]p < 0.001 | 0.945 [0.879–1.0]p < 0.001 | 0.695 [0.636–0.753]p < 0.001 |
| Roche | |||||
| n (%) | 8 (10.0) | 14 (37.8) | 23 (88.5) | 27 (90.0) | |
| 95% CI | 4.4–18.8 | 22.4–55.2 | 69.8–97.6 | 73.5–97.9 | |
| AUC [95% CI] | 0.539 [0.458–0.621]p = 0.334 | 0.700 [0.586–0.814]p < 0.001 | 0.938 [0.859–1.0]p < 0.001 | 0.984 [0.883–1.0]p < 0.001 | 0.704 [0.647–0.762]p < 0.001 |
| OCD | |||||
| n (%) | 13 (16.3) | 21 (56.8) | 23 (88.5) | 27 (90.0) | |
| 95% CI | 8.9–26.2 | 39.5–72.9 | 69.8–97.6 | 73.5–97.9 | |
| AUC [95% CI] | 0.566 [0.484–0.648]p = 0.107 | 0.731 [0.664–0.879]p < 0.001 | 0.938 [0.859–1.0]p < 0.001 | 0.966 [0.912–1.0]p < 0.001 | 0.735 [0.670–0.791]p < 0.001 |
| Siemens | |||||
| n (%) | 9 (11.3) | 12 (32.4) | 21 (80.8) | 28 (93.3) | |
| 95% CI | 5.3–20.3 | 18.0–49.8 | 60.6–93.4 | 77.9–99.2 | |
| AUC [95% CI] | 0.553 [0.471–0.635]p = 0.197 | 0.671 [0.557–0.786]p = 0.002 | 0.896 [0.798–0.993]p < 0.001 | 0.984 [0.883–1.0]p < 0.001 | 0.698 [0.640–0.756]p < 0.001 |
| cPass | |||||
| n (%) | 8 (10.0) | 18 (48.6) | 22 (84.6) | 29 (96.7)c | |
| 95% CI | 4.4–18.8 | 31.9–65.6 | 65.1–95.6 | 82.8–99.9 | |
| AUC [95% CI] | 0.546 [0.464–0.625]p = 0.259 | 0.743 [0.633–0.853]p < 0.001 | 0.917 [0.828–1.0]p < 0.001 | 0.983 [0.944–1.0]p < 0.001 | 0.720 [0.663–0.776]p < 0.001 |
AUC, area under curve; CI, confidence interval.
a
Significant difference in sensitivity between OCD and Beckman at 7–13 days of symptoms, where OCD performed better by 27.1% (95% CI 5.4–48.8; p = 0.019). Significant difference in sensitivity between OCD and Siemens at 7–13 days of symptoms, where OCD performed better by 24.4% (95% CI 2.4–46.3; p = 0.035).
b
Day 1–6: 1 equivocal and 3 insufficient omitted; Day 7–13 and Day 14–20: 1 equivocal and 1 insufficient omitted; Day ≥ 21: 1 equivocal omitted.
c
The 1 non-reactive subject was also non-reactive for all the other 5 tests. With n = 29, the 100% sensitivity has a lower 95% CI of 88.0%.