TABLE 2.
Sensitivities, specificities, and predictive values for Directigen rapid antigen immunoassay and LightCycler PCR assay compared to the results of culture for detection of GAS from throat swabsa
| Type of assay | Sensitivity (%) | Specificity (%) | Positive predictive value (%) | Negative predictive value (%) |
|---|---|---|---|---|
| Directgen antigen immunoassay | 55 (41, 68)b | 99 (98, 100) | 97 (83, 100) | 93 (90, 95) |
| LightCycler PCR assay | 93 (82, 98)b | 98 (96, 99) | 88 (77, 95) | 99 (97, 100) |
a
The prevalence rate of positive cultures was 14.3%. Values in parentheses are 95% confidence intervals.
b
Signficantly different by McNemar's test (P < 0.001).