TABLE 10.
Sensitivities, specificities, and predictive values of three HBsAg assays
| Test | Result | No. of samples with result of:
|
% Sensitivity | % Specificity | % NPVa | % PPVb | |
|---|---|---|---|---|---|---|---|
| HBsAg positive | HBsAg negative | ||||||
| Elecsys HBsAg | Positive | 702 | 0 | 100 | 100 | 100 | 100 |
| Negative | 0 | 2,611c | |||||
| Auszyme Monoclonal B | Positive | 589 | 1 | 96.6 | 99.9 | 98.0 | 99.8 |
| Negative | 21 | 1,036c | |||||
| IMx HBsAg | Positive | 266 | 51 | 89.3 | 97.6 | 98.5 | 84.2 |
| Negative | 32 | 2,112c | |||||
a
NPV, negative predictive value.
b
PPV, positive predictive value.
c
Three anti-HCV-positive serum samples (one sample from an IVDA and one from a homosexual individual) were excluded from the calculation of specificity since there was not enough sample material available for confirmatory testing and/or no further HBV serological parameters were available or HBV serology was inconclusive.