The coefficient of variation is commonly used to express what aspect of clinical measurements?

• A. Precision.
• B. Accuracy.
• C. Sensitivity.
• D. Specificity.

Answer: (A)

Coefficient of variation measures how consistent repeated clinical measurements are, i.e., precision. It’s calculated as the standard deviation divided by the mean and is often expressed as a percentage, which allows comparison of variability across different scales. A small CV means measurements cluster tightly around the mean (high precision), while a large CV indicates more spread (lower precision). It does not assess closeness to the true value, which is accuracy, because CV reflects variability rather than bias. Sensitivity and specificity pertain to diagnostic test performance, not the variability of measurement methods.