If a diagnostic test has high sensitivity, what does this imply about false negatives?

• A. There are many false negatives.
• B. It implies the test has a high false positive rate.
• C. There are some false negatives.
• D. There are few false negatives.

Answer: (D)

High sensitivity means the test is very good at identifying people who truly have the disease. Sensitivity is calculated as true positives divided by the sum of true positives and false negatives. If sensitivity is high, the number of false negatives must be small, so there are few false negatives. Therefore, a negative result from a highly sensitive test is fairly reliable for ruling out the disease. This concept is distinct from false positives, which relate to specificity, not sensitivity.