The "normal range" problem in the practice of clinical pathology

Area of Science:

• Clinical Pathology
• Laboratory Medicine
• Diagnostic Criteria

Background:

• Reference values are crucial for interpreting laboratory test results.
• Current practices may not always distinguish between reference values for diagnosis and therapy support.
• This distinction is vital for accurate clinical decision-making.

Purpose of the Study:

• To highlight the critical differences between reference values used for diagnosis and those used for therapy support.
• To advocate for pathologists to report context-specific reference values.
• To improve the utility of laboratory testing in clinical practice.

Main Methods:

• Conceptual analysis of reference value application in clinical pathology.
• Review of diagnostic criteria versus normal range criteria.
• Discussion of implications for patient care and laboratory reporting.

Main Results:

• Diagnostic reference criteria are derived from disease-specific comparisons, contrasting affected and unaffected individuals.
• Therapy support reference criteria typically use a physiologically normal benchmark (normal ranges).
• Failure to differentiate can lead to misinterpretation of patient results.

Conclusions:

• Pathologists should report reference values tailored to the specific clinical context (diagnosis or therapy support).
• Reporting both types of reference values when the testing purpose is unclear enhances diagnostic accuracy and therapeutic guidance.
• Implementing context-specific reference value reporting can significantly enhance patient care and clinical outcomes.