Epi

Negative Predictive Value

search

Negative Predictive Value

  • See Also
  1. Screening Test
  2. Contingency Grid or Cross Tab (includes Statistics Example)
  3. Bayes Theorem (Bayesian Statistics)
  4. Fagan Nomogram
  5. Experimental Error (Experimental Bias)
  6. Lead-Time Bias
  7. Length Bias
  8. Selection Bias (Screening Bias)
  9. Likelihood Ratio (Positive Likelihood Ratio, Negative Likelihood Ratio)
  10. Number Needed to Screen (Number Needed to Treat, Absolute Risk Reduction, Relative Risk Reduction)
  11. Positive Predictive Value
  12. Pre-Test Odds or Post-Test Odds
  13. Receiver Operating Characteristic
  14. Test Sensitivity (False Negative Rate)
  15. Test Specificity (False Positive Rate)
  16. U.S. Preventive Services Task Force Recommendations
  • 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)