TABLE 3.
Performance of illumigene assay and bacterial culture for detection of GAS in throat swabs using composite gold standarda for culture-positive specimens and culture result as gold standard for culture-negative specimens
| Method | No. of samples with the following resultb: |
% sensitivity (95% CI) | % specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | |||
|---|---|---|---|---|---|---|---|---|
| TPc | FP | TN | FN | |||||
| Culture | 93 | 0 | 631 | 34 | 73.2 (64.5–80.5) | 100 (99.2–100) | 100 (98.1–100) | 94.8 (92.9–96.4) |
| illumigene | 109 | 15 | 633 | 17 | 86.5 (80.0–91.7) | 97.6 (96.0–98.6) | 87.9 (80.5–92.8) | 97.3 (95.6–98.4) |
a
The composite gold standard was either a positive culture result or positive results by two molecular tests.
b
TP, true positive; FP, false positive; TN, true negative; FN, false negative.
c
A true-positive result was defined as positivity for GAS by culture or two molecular tests.