What does specificity measure in medical testing?

Specificity in medical testing refers to the ability of a test to correctly identify patients who do not have a particular disease. It is defined as the percentage of patients without the disease who receive a negative test result. In other words, high specificity indicates that the test effectively minimizes false positive results, thereby correctly identifying those who are disease-free.

When a test has high specificity, it means that if the test result is positive, there is a high likelihood that the patient actually has the disease. Conversely, a test with low specificity might lead to many healthy patients being incorrectly labeled as having the disease, resulting in unnecessary anxiety or treatment. Thus, understanding specificity is essential for interpreting test results accurately and ensuring proper patient management.

The other options describe different concepts related to diagnostic testing: one option discusses the rate of false positives, another focuses on the ability to detect disease in patients known to have it (known as sensitivity), and the final option pertains to overall diagnostic accuracy rather than the specific measure of specificity.