Table 2.
Estimated clinical sensitivity of SQ-RAT in comparison with four rRT-PCR tests
| RdRp Ct stratum* | Sensitivity results | Specimens of newly diagnosed COVID-19 patients with upper respiratory tract infection in Korea | |||||
|---|---|---|---|---|---|---|---|
| All rRT-PCR tests (%) (N = 33,294) | Allplex (%) (N = 25,650) | PowerChek (%) (N = 3,935) | Standard M (%) (N = 1,942) | Real-Q (%) (N = 1,762) | |||
| Proportion of each stratum | ≤ 14.9 | 100 | 6.9 | 6.5 | 1.9 | 23.2 | 4.7 |
| 15.0–19.9 | 88.6 | 20.6 | 20.2 | 17.8 | 24.5 | 28.5 | |
| 20.0–24.9 | 55.4 | 21.6 | 21.6 | 19.9 | 21.0 | 26.9 | |
| 25.0–29.9 | 16.9 | 23.2 | 23.6 | 24.5 | 16.3 | 22.9 | |
| 30.0–34.9 | 2.9 | 24.9 | 25.0 | 33.6 | 14.2 | 15.1 | |
| ≥ 35.0 | 0 | 2.8 | 3.1 | 2.3 | 0.8 | 1.9 | |
| LoD of SQ-RAT | ≤ 23.37 | 81.4 | 42.0 | 41.1 | 33.4 | 62.9 | 52.7 |
| > 23.37 | 10.6 | 58.0 | 58.9 | 66.6 | 37.1 | 47.3 | |
| Estimated clinical sensitivity of SQ-RAT*,† | 41.8 | 41.1 | 33.8 | 59.7 | 49.2 | ||
*based on SD biosensor Standard MnCoV results; †Sum of all clinical sensitivity values in the Ct strata multiplied by the corresponding proportion in Fig. 1.
Abbreviations: Allplex, Allplex 2019-nCoV; COVID-19, coronavirus disease 2019; Ct, threshold cycle; PowerChek, PowerChek 2019 nCoV; LoD, limit of detection; Real-Q, Real-Q 2019-nCoV; RdRp, RNA-dependent RNA polymerase gene; rRT-PCR, real-time reverse-transcription PCR; SQ-RAT, SD Biosensor Q rapid antigen test; Standard M, Standard M nCoV.