Table 3.
Diagnostic accuracy of the COVID-19 speed antigen test in comparison with RT-qPCR
| Sensitivity (%), mean (95% CI) | Specificity (%), mean (95% CI) | Negative predictive value (%), mean (95% CI) | Positive predictive value (%), mean (95% CI) | |
|---|---|---|---|---|
| Overall population | 69.57 (54.25–82.26) | 99.89 (99.41–100) | 98.54 (97.56–99.20) | 96.97 (84.24–99.92) |
| Strongly positive (Ct < 23) | 100 (86.77–100) | — | — | 100 (86.77–100) |
| Positive (23 ≤ Ct < 33) | 46.15 (19.22–74.87) | — | — | 100 (54.07–100) |
| Low positive (Ct ≥ 33) | 0 (0–40.96] | — | — | 0 (0–40.96) |
| Symptomatic | 82.86 (66.35–93.44) | 99.77 (98.74–99.99) | 98.65 (97.09–99.50) | 96.67 (82.78–99.92) |
| Asymptomatic | 27.27 (6.02–60.97) | 100 (99.27–100) | 98.43 (96.93–99.32) | 100 (29.24–100) |
Symptomatic means the presence of a clinical picture compatible with severe acute respiratory syndrome coronavirus 2 infection, as described in the text. CI, confidence interval; Ct, cycle threshold.