Table 3.
Performance of total antibody screening assays in blind diagnostic evaluation using the validation set (n = 807 samples).
| Specificity at defined thresholds (95% CI) | Sensitivity for Acute COVID-19 at defined thresholds (95% CI) | Sensitivity for Early Convalescent COVID-19 at defined thresholds (95% CI) | Sensitivity for Late COVID-19 at defined thresholds (95% CI) | Optimal Threshold Value (method) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Threshold* | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 | |
| N Pan ELISA | 99.5 (98.4 - 99.8) |
98.8 (97.5 - 99.4) |
97.4 (95.8 - 98.4) |
61.7 (47.2 - 74.4) |
61.7 (47.2 - 74.4) |
61.7 (47.2 - 74.4) |
70.5 (61.1 - 78.4) |
77.1 (68.1 - 84.2) |
81.9 (73.3 - 88.2) |
77.1 (65.9 - 85.5) |
81.4 (70.6 - 88.9) |
85.7 (75.4 - 92.1) |
(2) |
| RBD Pan ELISA | 99.3 (98.2 - 99.7) |
99.3 (98.2 - 99.7) |
99 (97.7 - 99.5) |
38.3 (25.6 - 52.8) |
46.8 (33.1 – 61) |
57.4 (43.1 - 70.7) |
63.8 (54.2 - 72.4) |
65.7 (56.1 - 74.2) |
73.3 (64.1 - 80.9) |
80 (69 - 87.8) |
81.4 (70.6 - 88.9) |
87.1 (77.1 - 93.2) |
(3) |
| Spike Pan ELISA | 97.3 (95.9 - 98.5) |
96.7 (95.2 – 98.1) |
96.7 (95.2 – 98.1) |
76.6 (62.5 - 86.6) |
76.6 (62.5 - 86.6) |
76.6 (62.5 - 86.6) |
93.3 (88.6 – 97.1) |
94.3(87.8 - 98.1) | 94.3 (87.8 - 98.1) |
95.7 (87.5 - 98.6) |
95.7 (87.5 - 98.6) |
95.7 (87.5 - 98.6) |
(1) |
| Spike-RBD Bridging LIPS | 97.6 (96 - 98.6) |
96 (94.1 - 97.4) |
98.5 (97.1 - 99.2) |
80.9 (67.1 - 89.7) |
80.9 (67.1 - 89.7) |
78.7 (64.8 - 88.2) |
92.4 (85.5 - 96.1) |
92.4 (85.5 - 96.1) |
92.4 (85.5 - 96.1) |
94.3 (85.7 - 97.8) |
94.3 (85.7 - 97.8) |
94.3 (85.7 - 97.8) |
(3) |
*Threshold method key: 1 - 99th Percentile; 2 - 98th percentile; 3 - Jmax i.e., highest Youden IndexFigure headings.
For each candidate screening assays, one value for specificity of the assays is reported, and sensitivity estimates are provided for COVID-19 samples taken at different time periods (Acute, Early Convalescent and Late Convalescent) post infection are reported for each of the threshold methods. Confidence intervals (95% CI) are given for each estimate. The optimal threshold methods was determined by finding the value which provided at least (or as near to) 98% specificity, whilst offering the optimal sensitivity.