What does CVG denote?

• A. Inter-individual biological variation
• B. Intra-individual variation
• C. Analytical variation
• D. Population variation

Answer: (A)

CVG refers to the between-subject, or inter-individual, component of biological variation. When you measure a biomarker across many healthy individuals, part of the spread in values comes from differences between people (genetics, age, lifestyle, etc.), not from how a single person’s value changes over time. That between-person variability is quantified as CV_G.

In contrast, the within-subject variation (CV_I) describes how much a single individual’s value fluctuates over time, and analytical variation (CV_A) reflects the imprecision of the assay itself. The term “population variation” isn’t a standard designation in this framework. Therefore, CV_G correctly denotes inter-individual biological variation.