TABLE 2.
Relative performance of each assay compared to that when the criterion was positivity by at least two of the testsa
| Test | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) |
|---|---|---|---|---|
| Culture | 92.9 | 100 | 100 | 98.9 |
| DFA assay | 59.5 | 99.6 | 96.2 | 93.9 |
| PCR | 92.9 | 96.2 | 79.6 | 98.8 |
| OIA | 73.8 | 100 | 100 | 96 |
a
These calculations do not consider data for 7 of 10 patients with positive PCR results, in whom chlamydial EBs were seen. Had data for these patients been included, the sensitivity of PCR would be 93.8%, while the sensitivities of culture, the DFA assay, and OIA would have decreased to 79.6, 50, and 63.2%, respectively (see Discussion). PPV, positive predictive value; NPV, negative predictive value.