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Negative Predictive Value
Aka: Negative Predictive Value
- See Also
- Screening Test
- Contingency Grid (includes Statistics Example)
- Test Sensitivity
- Test Specificity
- Positive Predictive Value
- Likelihood Ratio
- Number Needed to Screen
- Length Bias
- Leadtime Bias
- Selection Bias
- Definition
- Patients with negative test that do not have disease
- Assesses reliability of negative test
- Indications
- Puts Test Sensitivity in context of disease Prevalence
- Lower disease Prevalence results in higher NPV
- Test Sensitivity effect minimized at low Prevalence
- False negatives decrease substantially
- Results in more reliable negative test
- Calculation
- NPV = (True negative) / (true and false negatives)