Final answer:
Test sensitivity measures the ability of a test to correctly identify those with a condition. It is calculated by dividing true positives by the sum of true positives and false negatives. A highly sensitive test effectively rules out a disease with a negative result.
Step-by-step explanation:
The sensitivity of a test measures the proportion of individuals with a particular condition (such as an infection) who are correctly identified by the test as having the condition. This is an important concept in the field of medicine, especially when diagnosing diseases. To calculate the sensitivity of a test, you divide the number of true positive results by the sum of true positive and false negative results. The formula can be expressed as Sensitivity = True Positives / (True Positives + False Negatives).
This measure is typically expressed as a percentage, where a higher percentage indicates a higher sensitivity of the test. A highly sensitive test is ideal for ruling out a disease because a negative test result would confidently suggest that the disease is absent. However, if a patient tests negative on a highly sensitive test, the likelihood that the person is infected is generally quite low.