How is sensitivity defined in diagnostic testing?

Sensitivity in diagnostic testing refers to the ability of a test to correctly identify individuals who have a particular disease or condition. It is quantified by the ratio of true positives to the total number of individuals who truly have the disease, which encompasses both true positives and false negatives. This relationship is represented by the formula:

Sensitivity = True Positives (TP) / (True Positives (TP) + False Negatives (FN))

This measure is crucial in clinical practice because a high sensitivity indicates that the test is effective at detecting the disease in individuals who have it, thereby minimizing the risk of missing a diagnosis. It is particularly important in screenings for serious conditions where early detection significantly impacts patient outcomes, such as cancer screenings.

In summary, sensitivity is a vital parameter for understanding how well a diagnostic test performs in identifying those with a disease, making it essential for ensuring health interventions are properly directed.