Define sensitivity in epidemiology?

Sensitivity in epidemiology refers to the ability of a diagnostic test or screening tool to correctly identify individuals who have a particular disease or condition. It is a measure of the test's ability to detect true positive cases accurately. Sensitivity is calculated by dividing the number of true positive results by the sum of true positive and false negative results, and it is expressed as a percentage. A highly sensitive test will have a low rate of false negatives, meaning it will correctly identify most individuals with the disease. Sensitivity is an important parameter in evaluating the performance of diagnostic tests and screening programs in epidemiological studies.