Table 3.
Sensitivity, specificity, positive predictive value, and negative predictive value of IgG detection in serum samples for the diagnosis of active and cured COVID-19. PPV, positive predictive value; NPV, negative predictive value; NA, not applicable.
| IgG determination | Diagnostic performance | |||||
|---|---|---|---|---|---|---|
| Positive | Negative | Sensitivity | Specificity | PPV | NPV | |
| Cohort 1 | ||||||
| Proven and probable COVID-19 (n = 56) | ||||||
| ≤ 7 from onset of symptoms | 19 | 11 | 63.3 | 100 | 100 | 42.1 |
| > 7 from onset of symptoms | 15 | 11 | 57.7 | 100 | 100 | 8.3 |
| Overall | 34 | 22 | 60.7 | 100 | 100 | 29.3 |
| Proven COVID-19 (n = 49) | ||||||
| ≤ 7 from onset of symptoms | 16 | 10 | 61.5 | 100 | 100 | 44.4 |
| > from onset of symptoms | 13 | 10 | 56.5 | 100 | 100 | 9.1 |
| Overall | 29 | 20 | 59.2 | 100 | 100 | 31.1 |
| COVID-19 free (n = 9) | 0 | 9 | NA | NA | NA | NA |
| Cohort 2 | ||||||
| Proven and probable cured COVID-19 (n = 40) | ||||||
| Overall | 30 | 10 | 75 | 84.6 | 79 | 81.5 |
| Proven cured COVID-19 (n = 39) | ||||||
| Overall | 29 | 10 | 74.4 | 84.6 | 78.4 | 81.5 |
| COVID-19 free (n = 52) | 8 | 44 | NA | NA | NA | NA |