Which property allows an index to detect small changes in health status?

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

Answer: (B)

The ability to detect small changes in health status is best described by sensitivity. This property, sometimes thought of as responsiveness, reflects how well an index can pick up even minor improvements or deteriorations over time. If an index is highly sensitive, you’ll notice subtle shifts in a patient’s condition from one assessment to the next, which is crucial for monitoring progress and making timely decisions. Reliability means the measure is consistent across trials, validity means it actually measures what it intends to measure, and quantifiability is about expressing results in numbers. None of those guarantee that small, meaningful changes will be captured, whereas sensitivity specifically ensures those tiny yet important changes are detected.