What does CVA stand for?

• A. Analytical variation/imprecision
• B. Clinical variation assessment
• C. Absolute variation
• D. Comparative variation analysis

Answer: (A)

This question tests understanding of what CVA stands for in the laboratory context, specifically the source of measurement variability. CVA refers to Analytical Variation (Imprecision), which is the portion of total test variability attributable to the measurement process itself—instrument noise, reagents, calibration, and how the assay is performed. It reflects how repeatable the same sample is when measured under the same conditions. Distinguishing this from biological or clinical variation is key: clinical variation is about true differences between patients or biological states, not about how precisely a test is measuring the same sample. A low analytical variation means the assay is reliable and reproduces similar results on repeated runs; a high analytical variation suggests issues with the assay that may need recalibration, better instrumentation, or protocol optimization. The other terms don’t describe the precision of the measurement method, which is why analytical variation/imprecision is the correct interpretation.