What is the MDC for the LEFS?

What is the MDC for the LEFS?

• A. 3
• B. 9
• C. 6
• D. 12

Answer: (B)

The main idea here is Minimal Detectable Change, which is the smallest amount of change that exceeds measurement error and reflects a real change in a patient’s status, with a given level of confidence (usually 95%). For the Lower Extremity Functional Scale, which ranges from 0 to 80, the MDC at 95% confidence is about 9 points. This means you can be roughly 95% confident that a change of 9 points or more represents real improvement or decline in function, not just random measurement variation. Changes smaller than 9 could fall within the test’s error range and might not reflect true change. So the value around 9 is the standard threshold used to interpret real change on the LEFS; smaller changes are likely due to measurement noise, while a 9-point change is the commonly cited benchmark.

The main idea here is Minimal Detectable Change, which is the smallest amount of change that exceeds measurement error and reflects a real change in a patient’s status, with a given level of confidence (usually 95%).

For the Lower Extremity Functional Scale, which ranges from 0 to 80, the MDC at 95% confidence is about 9 points. This means you can be roughly 95% confident that a change of 9 points or more represents real improvement or decline in function, not just random measurement variation. Changes smaller than 9 could fall within the test’s error range and might not reflect true change.

So the value around 9 is the standard threshold used to interpret real change on the LEFS; smaller changes are likely due to measurement noise, while a 9-point change is the commonly cited benchmark.