The negative predictive value (NPV) of a test relates to how believable a negative test is within a given population. Negative predictive value is important with diagnostic tests that are designed to detect healthy people.
For negative predictive value, researchers focus on this part of the 2x2 table:
Everyone in the calculation for negative predictive value tested "negative" using the diagnostic test. Thus, researchers can calculate the proportion of people without the disease as measured by "gold standard" that tested "negative" using the test. With higher values of negative predictive value, the "believability" or confidence of the test increases.
Here is the formula for negative predictive value:
Negative Predictive Value (NPV)
Click on the Diagnostic Accuracy button to continue.