Table 3.
Measures of diagnostic accuracy of FebriDx MxA for identification of any respiratory virus, compared to the reference standard of PCR positivity, n = 248.
| n/n | Value (95%CI) | |
|---|---|---|
| Prevalence of any virus* | 135/248 | 54 (48 to 61) |
| SARS-CoV-2 (COVID-19) | 118/248 | 48 (41 to 54) |
| Rhino/enterovirus | 10/248 | 4 (2 to 7) |
| Human Metapneumovirus | 4/248 | 2 (1 to 4) |
| Human Coronavirus OC43 | 2/248 | 2 (1 to 4) |
| Human Coronavirus HKU1 | 1/248 | 1 (0 to 2) |
| Human Coronavirus NL63 | 1/248 | 1 (0 to 2) |
| Sensitivity† | 117/135 | 87 (80 to 92) |
| Specificity | 102/113 | 90 (83 to 95) |
| Positive predictive value | 117/128 | 91 (86 to 94) |
| Negative predictive value | 112/120 | 85 (78 to 90) |
| Positive likelihood ratio | 8.9 (5.1 to 15.7) | |
| Negative likelihood ratio | 0.15 (0.1 to 0.23) | |
| Overall accuracy | 219/248 | 88 (83 to 92) |
CI=Confidence interval. *One patient had co-detection of SARS-CoV-2 and HCoV HKU1. † Viral detections associated with false negative MxA were: SARS-CoV-2 × 8, Rhino/enterovirus x 7 and Human Coronavirus x 3.