Table 1.
Comparison of rapid antigen tests of four different distributors
| Test distributora | PCR Ct ≤ 25 | PCR Ct ≤ 30 | PCR Ct > 30 | PPV (CI) PCR Ct cutoff 30 | Total number of samples |
|---|---|---|---|---|---|
|
N (Ag+/Ag−) % positive (95% CI) |
N (Ag+/Ag−) % positive (95% CI) |
N (Ag+/Ag−) % positive | PPV (CI 95%) | ||
| Abbotta | 18 (15/3) 83.3%(58.6–96.4%) | 39 (31/8) 79.5% (63.5–90.7%) | 43 (11/32) 25.6% | 73.8 (62.3–82.8%) | 82 |
| CLMSRDLa | 10 (6/4) 60%(26.2–87.8%) | 31 (14/17) 45.2%(27.3–64.0%) | 54 (5/49) 9.3% | 73.7 (52.7–87.6%) | 85 |
| DIALABa | 12 (12/0) 100%(73.5–100%) | 36 (32/4) 88.9%(73.9–96.9%) | 63 (29/34) 46.0% | 52.5 (45.2–59.6%) | 99 |
| Rochea | 9 (9/0) 100%(66.4–100%) | 32 (27/5) 84.4%(67.2–94.7%) | 39 (16/23) 41.0% | 62.8 (53.0–71.7%) | 71 |
Confidence intervals (CI 95%) for antigen tests sensitivities in relation to ct values ≤25 and ≤30 are given in parentheses. Sensitivity and positive predictive value infections (PPV) using PCR Ct values as reference (>30 defined as non-infectious and ≤30 and ≤25 as infectious); N = number.
a
For details of tests, see Methods section.