Table A1.
Detailed comparison of RT-PCR and antigen test (AGT) for individual tests stratified by cycle threshold (Ct): Strongly positive (Ct ≤ 20), Positive (20 < Ct ≤ 30), Weakly positive (30 < Ct ≤ 40), and Negative (Ct > 40). For better orientation, true positive and true negative values for individual tests are highlighted in grey.
| PCR Result | Patients (N) | ATG Result | Discrepancies N (%) | |||
|---|---|---|---|---|---|---|
| ATG Positive | ATG Negative | of Which Viable Virus 3 |
||||
| N (%) 1 | N (%) 1 | N (%) 2 | ||||
| Ecotest | PCR-positive | 107 | 81 (76%) | 26 (24%) | 26 (79%) | 3 (12%) |
| Strongly positive | 5 | 5 (100%) | 0 (NA) | 0 (0%) | 0 (N/A) | |
| Positive | 56 | 54 (96%) | 2 (4%) | 2 (6%) | 2 (100%) | |
| Weakly positive | 46 | 22 (48%) | 24 (52%) | 24 (73%) | 1 (4%) | |
| PCR-negative | 211 | 7 (3%) | 204 (97%) | 7 (21%) | 0 (0%) | |
| Total | 318 | 88 (28%) | 230 (72%) | 33 | ||
| JoysBio | PCR-positive | 90 | 52 (58%) | 38 (42%) | 38 (95%) | 4 (11%) |
| Strongly positive | 2 | 2 (100%) | 0 (0%) | 0 (0%) | 0 (N/A) | |
| Positive | 43 | 38 (88%) | 5 (12%) | 5 (13%) | 3 (60%) | |
| Weakly positive | 45 | 12 (27%) | 33 (73%) | 33 (82%) | 1 (3%) | |
| PCR-negative | 135 | 2 (1%) | 133 (99%) | 2 (5%) | 0 (0%) | |
| Total | 225 | 54 (24%) | 171 (76%) | 40 | ||
| ND COVID | PCR-positive | 77 | 54 (70%) | 23 (30%) | 23 (37%) | 8 (35%) |
| Strongly positive | 0 | 0 (NA) | 0 (NA) | 0 (0%) | 0 (N/A) | |
| Positive | 36 | 30 (83%) | 6 (17%) | 6 (8%) | 6 (100%) | |
| Weakly positive | 41 | 24 (59%) | 17 (41%) | 17 (23%) | 2 (12%) | |
| PCR-negative | 114 | 50 (44%) | 64 (56%) | 50 (68%) | 0 (0%) | |
| Total | 191 | 104 (54%) | 87 (46%) | 73 | ||
| Standard Q | PCR-positive | 42 | 26 (62%) | 16 (38%) | 16 (94%) | 4 (25%) |
| Strongly positive | 1 | 1 (100%) | 0 (NA) | 0 (0%) | 0 (N/A) | |
| Positive | 22 | 18 (82%) | 4 (18%) | 4 (24%) | 3 (75%) | |
| Weakly positive | 19 | 7 (37%) | 12 (63%) | 12 (71%) | 1 (8%) | |
| PCR-negative | 97 | 1 (1%) | 96 (99%) | 1 (6%) | 0 (0%) | |
| Total | 139 | 27 (19%) | 112 (81%) | 17 | ||
| VIVA diag | PCR-positive | 91 | 38 (42%) | 53 (58%) | 53 (88%) | 9 (17%) |
| Strongly positive | 0 | 0 (0%) | 0 (NA) | 0 (0%) | 0 (N/A) | |
| Positive | 39 | 27 (69%) | 12 (31%) | 12 (20%) | 7 (58%) | |
| Weakly positive | 52 | 11 (21%) | 41 (79%) | 41 (68%) | 2 (5%) | |
| PCR-negative | 177 | 7 (4%) | 170 (96%) | 7 (12%) | 0 (0%) | |
| Total | 268 | 45 (17%) | 223 (83%) | 60 | ||
1 percentage of the reference RT-PCR result; 2 percentage of discrepancies between RT-PCR and AGT in the respective group; 3 percentage of samples with viable virus out of the discrepant results in the respective group.