The reference change value: a proposal to interpret laboratory reports in serial testing based on biological...

Area of Science:

• Clinical Laboratory Science
• Biostatistics
• Analytical Chemistry

Background:

• Clinical laboratory testing involves serial measurements for patient monitoring.
• Interpreting numerical changes in serial results requires objective criteria.
• The reference change value (RCV) is proposed as an objective guide.

Purpose of the Study:

• To introduce and define the reference change value (RCV) for clinical laboratory serial testing.
• To establish a standardized, biologically-based criterion for interpreting changes in serial laboratory results.
• To provide a foundation for an objective guide to assess serial testing outcomes.

Main Methods:

• Compiled data from 191 publications on biological variation for numerous analytes.
• Utilized a database of biological variation to establish a standardized criterion for RCV calculation.
• Applied Harris's formula, incorporating desirable analytical quality specifications based on within-subject biological variation.

Main Results:

• Calculated the RCV for 261 different analytes.
• Determined RCVs based on half the within-subject biological variation at 95% probability.
• Developed a guide for a common criterion to identify clinically significant changes in serial results.

Conclusions:

• The reference change value (RCV) offers a practical approach for laboratories to evaluate changes in serial test results.
• The RCV data presented serve as a starting point for a universally applicable objective interpretation guide.
• This study promotes objective interpretation of longitudinal laboratory data.