[The concept of reference change values (RCV). Will it supersede reference intervals?].

Area of Science:

• Clinical Chemistry and Hematology
• Biostatistics
• Medical Diagnostics

Context:

• Laboratory values are typically compared to population-based reference ranges to identify abnormalities.
• Distinguishing early pathological changes from normal biological variation can be challenging with standard reference ranges.
• Accurate interpretation is critical during the nascent stages of a disease process.

Purpose:

• To introduce the concept of the reference change value (RCV) as a superior metric for interpreting laboratory results.
• To highlight the limitations of traditional population-based reference ranges in detecting subtle pathological changes.
• To emphasize the importance of personalized reference limits in clinical decision-making.

Summary:

• The reference change value (RCV) is calculated using measurement imprecision (1-5%) and within-person biological variability (≥100%).
• RCV defines the minimum difference between two measurements to be considered significant, irrespective of population reference ranges.
• This allows for the detection of significant changes before laboratory values exceed established normal ranges.

Impact:

• Utilizing RCV improves the accuracy of clinical decision-making for numerous analytes in clinical chemistry and hematology.
• Focusing on an individual's personal normal range, informed by RCV, enhances diagnostic sensitivity for early disease detection.
• This personalized approach provides a more clinically relevant interpretation of laboratory data compared to population norms.