TABLE 2.
Clinical performance comparison of three sample-to-answer EUA molecular assays for the detection of SARS-CoV-2 (n = 108)
| Molecular assay | Reference standarda |
Kappa (κ) (±95% CI)b |
PPA (±95% CI)b |
NPA (±95% CI)b |
|
|---|---|---|---|---|---|
| Positive | Negative | ||||
| Xpert Xpress | |||||
| Positive | 57 | 0 | 98.3 | 100 | |
| Negative | 1 | 50 | 0.98 (1–0.95) | (0.91–1) | (0.93–1) |
| ID NOWc | |||||
| Positive | 50 | 0 | 87.7 | 100 | |
| Negative | 7 | 50 | 0.87 (0.96–0.78) | (0.76–0.95) | (0.93–1) |
| ePlex | |||||
| Positive | 53 | 0 | 91.4 | 100 | |
| Negative | 5 | 50 | 0.91 (0.99–0.83) | (0.81–0.97) | (0.93–1) |
a
The reference standard was the Hologic Fusion assay. Data represent numbers of patients.
b
±95% CI, upper/lower 95% confidence interval (>0.90, almost perfect; 0.80 to 0.90, strong; 0.60 to 0.79, moderate; 0.40 to 0.59, weak; 0.21 to 0.39, minimal; 0 to 0.20, none).
c
ID NOW had one invalid result that was removed from the analysis which was positive by the reference standard and the other two methods.