What does specificity mean when used to describe medical tests?
No medical test is perfect. It is important to know the limitations of any test so you can judge how to factor in the test results to your treatment decisions. The specificity of a medical test is a measure of how well the test identifies people who do not have a particular disease. In other words, specificity is a way of measuring whether or not the test inaccurately flags normal people as having a condition. Example: We will use the same sample as above; 10 women, 3 of who have cancer. If the test identifies all three cancer patients but flags any normal women as having the disease, it would have 100% sensitivity but reduced specificity. The more normal women the test identifies as having cancer, the lower the specificity of the test.
