What does a high specificity in a test indicate?

High specificity in a medical test is crucial as it indicates the test's ability to correctly identify healthy individuals who do not have the disease. This means that when a test has high specificity, it is effective at minimizing false-positive results. A test with high specificity will rarely yield positive results when it is administered to healthy patients, thus ensuring that those who do not have the condition are accurately identified as such.

This attribute is particularly important in clinical practice because it helps prevent unnecessary anxiety and further invasive testing in patients who are actually healthy. It reinforces the accuracy and reliability of the test in determining the absence of disease, supporting better clinical decision-making.

In contrast, the other options would suggest various limitations or inaccuracies that don't align with the definition of specificity. For example, a false-negative rate does not correlate with high specificity; rather, it pertains to sensitivity. Additionally, high specificity does not suggest that the tool is not useful for diagnosis, nor does it imply that it is effective in identifying patients with the disease.