TABLE 4.
Performance characteristics of the four assays for GBS detection with antenatal vaginorectal specimensa
| Method | % Sensitivity (95% CI) | % Specificity (95% CI) | PPV (%) (95% CI) | NPV (%) (95% CI) |
|---|---|---|---|---|
| Culture | 42.3 (36-49) | 100 (99-100) | 100 (96-100) | 74.3 (70-78) |
| GBS antigen | 57.3 (51-64) | 99.5 (98-100) | 98.5 (95-100) | 79.5 (76-83) |
| cfb PCR | 75.3 (99-100) | 100 (99-100) | 100 (98-100) | 87.1 (84-90) |
| scpB PCR | 99.6 (98-100) | 100 (99-100) | 100 (99-100) | 99.7 (98-100) |
a
Abbreviations: PPV, positive predictive value; NPV, negative predictive value; CI, confidence interval.