What is the difference between sensitivity and specificity in laboratory tests?

Sensitivity and specificity are two fundamental concepts in the evaluation of diagnostic tests. Sensitivity refers to the test's ability to correctly identify individuals who have the disease, which is essentially measuring the proportion of true positive results among all actual positive cases. When we say a test has high sensitivity, it means that it is effective at detecting the condition, minimizing the number of false negatives—instances where the test fails to detect the disease when it is present.

Specificity, on the other hand, pertains to the test's ability to correctly identify individuals who do not have the disease, thereby measuring the proportion of true negative results among all actual negative cases. A test with high specificity is effective at ruling out the disease, minimizing false positives—instances where the test indicates a person has the disease when in fact they do not.

Thus, the choice that states sensitivity measures true positives and specificity measures true negatives accurately captures the essence of these two metrics, highlighting their respective roles in diagnostic test performance. This distinction is crucial for evaluating the reliability and applicability of laboratory tests in medical practice.