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The negative predictive value of a screening or diagnostic test indicates the likelihood that a person with a negative test result would actually not have the condition for which the test is used; i.e. the probability that a negative test result is correct.
The higher the value of the negative predictive value (e.g. 99% might be considered a high value), the more useful the test is for predicting that the person does not have the condition.
For example, the negative predictive value of a normal prostate specific antigen (PSA) test in prostate cancer screening is about 98%. This means it is very unlikely that men with a normal PSA test result on routine screening have the condition.
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