Table 2.
The performance of RADTs, all samples, all RT-PCR positive samples, and samples grouped according to Ct values of the N gene target in the LDT RT-PCR. Tested, n, number of tested samples. Same as ref: number of samples tested the same as reference LDT RT-PCR test, positive or negative. Tested pos, n, number of samples that were positive in RADT. Ag−/Ag+: Ct median of samples that were negative in RADT (Ag−) and Ct median of samples that were positive in RADT (Ag+). 1For virus culture experiments, at this rowthere are Ct median of samples that were negative in virus culture and Ct median of samples that were positive in virus culture.
| SOFIA QUIDEL | STANDARD Q SD BIOSENSOR | PANBIO ABBOTT | VIRUS CULTURE | ||
|---|---|---|---|---|---|
| All | Tested, n | 188 | 198 | 190 | 59 |
| samples | Same as ref | 159 | 168 | 164 | 18 |
| Agreement | 84.57 % | 84.85 % | 86.32 % | 30.51 % | |
| 95 % CI | 78.72−89.04 | 79.19−89.18 | 80.70−90.49 | 20.25−43.15 | |
| Ct median (Ag−/Ag+)1 | 31.75/20.97 | 31.17/20.95 | 31.08/20.98 | 29.33/19.261 | |
| All RT-PCR positive | Tested, n | 148 | 158 | 152 | 59 |
| Tested pos, n | 119 | 128 | 126 | 18 | |
| samples | Sensitivity | 80 % | 81 % | 83 % | 31 % |
| Agreement | 80.41 % | 81.01 % | 82.89 % | ||
| 95 % CI | 73.28−86.00 | 74.19−86.36 | 76.12−88.05 | ||
| RT-PCR | Tested, n | 89 | 97 | 92 | 20 |
| positives, | Tested pos, n | 88 | 96 | 90 | 16 |
| Ct<25 | Sensitivity | 99 % | 99 % | 98 % | 80 % |
| RT-PCR | Tested, n | 34 | 35 | 34 | 19 |
| positives, | Tested pos, n | 28 | 24 | 26 | 2 |
| Ct 25−29.99 | Sensitivity | 82 % | 69 % | 76 % | 11 % |
| RT-PCR | Tested, n | 123 | 132 | 126 | 39 |
| positives, | Tested pos, n | 116 | 120 | 116 | 18 |
| Ct<30 | Sensitivity | 94 % | 91 % | 92 % | 46 % |
| RT-PCR | Tested, n | 25 | 26 | 26 | 20 |
| positives, | Tested pos, n | 3 | 8 | 10 | 0 |
| Ct≥30 | Sensitivity | 12 % | 31 % | 38 % | 0% |
| RT-PCR | Tested, n | 40 | 40 | 38 | ND |
| negatives | Tested pos, n | 0 | 0 | 0 |