Which area is evaluated by sensitivity in screening tests?

Which area is evaluated by sensitivity in screening tests?

• A. The proportion of false positives in a screening test
• B. The probability that the screening test will be positive in someone with the disease (true positive rate)
• C. The probability of a negative test in a healthy person
• D. The overall accuracy of the screening test

Answer: (B)

Sensitivity measures how good a screening test is at identifying people who truly have the disease. It’s the true positive rate: the proportion of diseased individuals who test positive, calculated as TP divided by (TP plus FN). In screening, you want to minimize missed cases, so a highly sensitive test catches most people who actually have the condition, reducing false negatives. Context helps: sensitivity focuses on those with the disease, whereas specificity (the true negative rate) concerns healthy individuals—how often the test correctly yields a negative result for them. The overall accuracy combines correct identifications of both diseased and healthy people, not just the ability to detect disease. So, the statement that describes sensitivity is the test’s probability of being positive in someone with the disease.

Sensitivity measures how good a screening test is at identifying people who truly have the disease. It’s the true positive rate: the proportion of diseased individuals who test positive, calculated as TP divided by (TP plus FN). In screening, you want to minimize missed cases, so a highly sensitive test catches most people who actually have the condition, reducing false negatives.

Context helps: sensitivity focuses on those with the disease, whereas specificity (the true negative rate) concerns healthy individuals—how often the test correctly yields a negative result for them. The overall accuracy combines correct identifications of both diseased and healthy people, not just the ability to detect disease.

So, the statement that describes sensitivity is the test’s probability of being positive in someone with the disease.