Video - Sensitivity and specificity

Sensitivity and specificity are two important statistical measures used to evaluate the performance of medical tests, such as diagnostic tests for diseases.

Sensitivity measures the ability of a test to correctly identify those who have the disease. It is the proportion of people with a disease who test positive. This means that a test with high sensitivity can correctly identify most individuals who have the disease, while a test with low sensitivity will miss many cases of the disease. Sensitivity is calculated by dividing the number of true positives, by the total number of all people who have the condition - the true positives and false negatives.

Specificity, on the other hand, measures the ability of a test to correctly identify those who do not have the disease. It is the proportion of people without a disease who correctly test negative. This means that a test with high specificity can correctly identify most individuals who do not have the disease, while a test with low specificity will result in many false positive results. Specificity is calculated by dividing the number of true negatives by the total number of all people who don't have the condition - the true negatives and false positives.