If a test has a very high specificity, what is the likely impact on the test's negative predictive value (NPV)?

Understand the Problem

The question is asking about the relationship between a test's specificity and its negative predictive value (NPV), particularly how high specificity affects the NPV, considering the importance of prevalence in interpreting diagnostic test results.

Answer

The negative predictive value (NPV) is likely to increase.

If a test has very high specificity, the negative predictive value (NPV) is likely to increase. A highly specific test is good at identifying those who do not have the disease, leading to fewer false positives and a higher confidence in negative results.

More Information

Specificity and negative predictive value are important measures of a test's accuracy. Tests with high specificity are useful for confirming the absence of a disease.

Tips

Students may confuse specificity with sensitivity. Specificity measures the ability of a test to correctly identify those without the disease (true negatives), while sensitivity measures the ability of a test to correctly identify those with the disease (true positives).