What formula is used to define specificity in diagnostic testing?

Specificity in diagnostic testing is defined as the ability of a test to correctly identify individuals without the disease. The formula for specificity is represented as the number of true negatives divided by the total number of individuals who do not have the disease, which includes both true negatives and false positives.

In essence, specificity measures how effectively a test can rule out patients who do not have the condition, minimizing the number of false positive results. High specificity is particularly important in situations where a positive result could lead to unnecessary anxiety, further testing, or treatment.

Thus, the formula TN / (TN + FP) accurately captures this concept, presenting a clear calculation that allows healthcare providers to understand the reliability of a test in confirming that a condition is absent.