What does sensitivity measure in medical testing?

Sensitivity in medical testing refers specifically to the test's ability to correctly identify individuals who have the disease in question. It is defined as the proportion of true positives (individuals correctly identified as having the disease) out of the total number of individuals who truly have the disease. In other words, sensitivity measures how effectively a test can detect a condition when it is present.

For example, if a test has high sensitivity, it means that there are few false negatives; this is crucial in clinical practice because it ensures that most patients with the disease are correctly diagnosed. This is especially important for conditions where early detection and treatment significantly impact outcomes.

Understanding sensitivity is fundamental for evaluating the utility of a diagnostic test, as it not only informs clinicians about the likelihood that a positive result indicates the presence of disease but also influences screening strategies and helps in patient management decisions.