Table 1.
Diagnostic performance statistics of the Coris BioConcept COVID-19 Ag Respi-Strip test compared to the RealStar SARS-CoV-2 RT-PCR kit 1.0 assay obtained from the initial evaluation of 52 samples and the two-week real-life screening of 294 samples.
| Coris-Ag diagnostic performance statisticsa | Initial evaluation (15-min reading) (n = 52) | Coris-Ag: 15-min readingb (n = 294) | Coris-Ag: 30-min readingb (n = 294) | Period 1c(n = 158) | Period 2c(n = 136) |
|---|---|---|---|---|---|
| True positive | 8 | 16 | 19 | 16 | 3 |
| True negative | 41 | 252 | 252 | 131 | 121 |
| False positive | 0 | 0 | 0 | 0 | 0 |
| False negative | 3 | 26 | 23 | 11 | 12 |
| Sensitivity (%) | 72.0 | 38.1 | 45.2 | 59.3 | 20.0 |
| Specificity (%) | 100 | 100 | 100 | 100 | 100 |
| PPV (%) | 100 | 100 | 100 | 100 | 100 |
| NPV (%) | 93.0 | 90.6 | 91.6 | 92.2 | 91.0 |
| Positivity rate of RT-PCR (%)d | 22.6 | 14.3 | 14.3 | 17.1 | 11.0 |
| Positivity rate of Coris-Agd(%) | 15.4 | 5.4 | 6.5 | 10.1 | 2.2 |
| Coris-Ag accuracye(%) | 94.2 | 91.2 | 92.2 | 93.0 | 91.2 |
PPV = positive predictive value and NPV = negative predictive value.
Accuracy = (true positive + true negative/true positive + false negative + true negative + false positive).
Performance statistics of Coris-Ag were calculated for both 15- and 30-min readings and for Periods 1 and 2.
The 15-min and 30-min reading data were of all the 294 patients over the two weekly periods.
Periods 1 and 2 data were based on the 30-min readings.
Positivity rates indicated for RT-PCR and Coris Ag were for the period of the initial evaluation (column 2), either the whole two weeks (columns 3 and 4) or for each Periods 1 and 2 separately (columns 5 and 6).
Accuracy: overall probability that a patient will be correctly classified.