Which term describes a screening test's ability to correctly identify those who have the disease?

• A. Sensitivity
• B. Specificity
• C. Validity
• D. Reliability

Answer: (A)

Sensitivity is the ability of a screening test to correctly identify those who have the disease. It measures the true positive rate, meaning how many of the actual cases the test flags as positive. A test with high sensitivity catches most people who truly have the condition, so a negative result is more reliable for ruling out disease (the idea behind “SnNout”: if a highly sensitive test is negative, you can be confident the disease is not present). This focus on detecting actual cases makes sensitivity the term that best describes a screening test’s ability to identify those with the disease.

Specificity, on the other hand, is about correctly identifying those without the disease and minimizes false positives. Validity refers to whether a test measures what it’s supposed to measure overall, and reliability concerns consistency of results across repetitions or observers.