Epi

Negative Predictive Value

search

Negative Predictive Value

  • Definition
  1. Patients with negative test that do not have disease
  2. P(No Disease | negative test )
  3. Assesses reliability of negative test
  • Indications
  1. Puts Test Sensitivity in context of disease Prevalence
  2. Lower disease Prevalence results in higher NPV
    1. Test Sensitivity effect minimized at low Prevalence
    2. False negatives decrease substantially
    3. Results in more reliable negative test
  • Calculation
  1. NPV = (True negative) / (true and false negatives)