Sensitivity is defined as which of the following?

Sensitivity is defined as which of the following?

• A. The proportion of disease-free individuals who test negative.
• B. The proportion of true negatives among those without disease.
• C. The proportion of patients with the condition who test positive.
• D. The proportion of false negatives among those with disease.

Answer: (C)

Sensitivity measures how well a test identifies people who actually have the disease. It is the proportion of individuals with the condition who test positive, i.e., true positives divided by all people who have the disease. A high sensitivity means the test catches most cases of the disease, resulting in few false negatives. In practice, a highly sensitive test is useful for screening because a negative result can help rule out disease (when sensitivity is high, a negative test is less likely to miss a diseased person). The other ideas describe different concepts: the proportion of disease-free individuals who test negative (specificity), and the proportion of false negatives among those with the disease (the complement of sensitivity).

Sensitivity measures how well a test identifies people who actually have the disease. It is the proportion of individuals with the condition who test positive, i.e., true positives divided by all people who have the disease. A high sensitivity means the test catches most cases of the disease, resulting in few false negatives. In practice, a highly sensitive test is useful for screening because a negative result can help rule out disease (when sensitivity is high, a negative test is less likely to miss a diseased person).

The other ideas describe different concepts: the proportion of disease-free individuals who test negative (specificity), and the proportion of false negatives among those with the disease (the complement of sensitivity).