Table 5

Post-test probability of infection for those at lowest and highest risk, under three hypothetical diagnostic tests*

Probability of infection following a positive test, %Probability of infection following a negative test result, %
StudyRisk groupPretest probability of infection, %Test 1Test 2Test 3Test 1Test 2Test 3
*The sensitivity/specificity (%) of tests 1, 2, and 3 are 92/98, 95/98, and 98/98 respectively.
1Lowest0.724.525.125.70.060.040.01
Highest47.397.697.797.86.84.41.8
2Lowest4.166.367.067.70.340.220.09
Highest67.799.099.099.014.69.74.1
3Lowest4.869.970.571.20.410.260.10
Highest53.398.198.298.28.55.52.3
4Lowest2.756.156.957.60.230.140.06
Highest63.998.898.898.912.68.33.5