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. 2004 Jun 2;4:4. doi: 10.1186/1471-2490-4-4

Table 4.

Post-test probabilities (predictive values) of dipstick nitrites, leucyte-esterase and combinations of both tests in population sub-groups and different settings, based on pooled sensitivities, pooled specificities and pooled pre-test probabilities (prevalences).

Post-test probability (predictive value)

Pre-test Probability (prevalence) Nitrites Leucocyte-esterase One or both positive Both positive
Population
General population .15
- Test + .33 .27 .31 .89
- Test - .90 .91 .94 .91
Children .20
- Test + .61 .34 .58 .66
- Test - .88 .88 .95 .87
Pregnant women .06
- Test + .55 .10 .58 (.99)
- Test - .97 .97 .95 (.96)
Elderly .30
- Test + .88 .47 .55 (.90)
- Test - .89 .81 .90 (.86)
Surgery .15
- Test + .70 .27 .51 (.38)
- Test - .92 .91 .97 (.94)
Urology .15
- Test + .78 .68 .54
- Test - .93 .97 .98
Setting
Family physician .55
- Test + .84 .62 .76
- Test - .61 .69 .84
Outpatient .10
- Test + .56 .22 .32
- Test - .94 .94 .97
Inpatient .15
- Test + .41 .38 .38
- Test - .92 .93 .95
Emergency .15
- Test + .62 .41 .41
- Test - .92 .92 .98

(): based on one study only.