II. Definition
- Patients with negative test that do not have disease
- P(No Disease | negative test )
- Assesses reliability of negative test
III. 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
IV. Calculation
- NPV = (True negative) / (true and False Negatives)