Reference Change Value
Also written as: RCV — Reference Change Value
The minimum percentage change required between serial hormone measurements to indicate a statistically significant biological change.
Full Definition
Reference Change Value (RCV) represents the minimum change between consecutive test results that exceeds analytical and biological variation, indicating a true change in the patient's physiological state. The RCV is calculated using the analytical coefficient of variation and biological variation data, typically expressed as a percentage change. For hormone testing, RCV values help clinicians determine whether observed changes in serial measurements represent genuine biological changes or simply reflect normal variation. Different hormones have different RCV values: thyroid-stimulating hormone requires approximately 30% change, while testosterone may require 20-25% change to be considered significant. Understanding RCV prevents over-interpretation of minor fluctuations and guides appropriate follow-up testing intervals.
Usage
Usage note: Apply hormone-specific RCV values when interpreting serial measurements for clinical significance.
In Context
- "The 40% increase in TSH exceeded the reference change value, indicating genuine thyroid function deterioration." — Thyroid monitoring report
- "Changes below the reference change value should not prompt therapeutic adjustments without clinical correlation." — Laboratory interpretation guidelines