What is the primary focus of specificity in a diagnostic test?

The primary focus of specificity in a diagnostic test is to detect the absence of a disease. Specificity measures the test's ability to correctly identify patients who do not have the disease, thus minimizing the number of false-positive results. When a test is highly specific, it means that when the test indicates a negative result, there is a high level of confidence that the disease is indeed absent. This is crucial in clinical settings where accurately ruling out a disease is just as important as confirming its presence.

For instance, in the context of screening for diseases, high specificity ensures that individuals who do not have the disease are not misclassified as having it, thereby reducing unnecessary anxiety and potentially harmful follow-up procedures.