Worked example of a specific and sensitive test with low positive predictive value
|
Pop=100 000
Prevalence=1% Sensitivity=99% Specificity=99% | Infected (+) | Not infected (−) | PV |
| Positive test result (+) | 990 | 990 | Positive PV=50% |
| Negative test result (−) | 10 | 98 010 | Negative PV=99.99% |
| Total | 1000 | 99 000 |
PV, predictive value.