Determination and validation of reference intervals.

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Medical Diagnostics

Background:

• Reference intervals are essential for interpreting laboratory test results in clinical practice.
• Establishing these intervals involves defining appropriate populations and statistical methodologies.
• The clinical utility of reference intervals is influenced by factors like population selection and statistical analysis.

Purpose of the Study:

• To provide an overview of reference interval concepts and their application in medicine.
• To discuss methods for deriving reference intervals from healthy and patient populations.
• To review the impact of statistical methods on reference interval development and interpretation.

Main Methods:

• Discussion of population selection criteria for reference interval derivation.
• Review of statistical procedures for establishing reference intervals.
• Illustration of the limitations of population-based reference intervals concerning intra-individual variability.

Main Results:

• Reference intervals are derived from specific populations using various statistical approaches.
• The variability of test results within an individual poses a challenge to the interpretation of population-derived reference intervals.
• Despite laboratory efforts, clinical application of reference intervals often falls short of optimal guidance.

Conclusions:

• Reference intervals are a cornerstone of laboratory diagnostics, but their interpretation requires careful consideration of individual patient data.
• The inherent variability within individuals can limit the predictive value of population-based reference intervals.
• Effective utilization of reference intervals necessitates bridging the gap between laboratory science and clinical practice.