[Rational utilization of laboratory diagnosis]

Area of Science:

• Clinical Pathology
• Laboratory Medicine
• Diagnostic Testing

Background:

• Current laboratory utilization often fails to meet professional and financial standards.
• A shift towards rational laboratory use, driven by specific clinical questions, is necessary.
• Clinicians require comprehensive information for accurate laboratory data interpretation, which is frequently lacking.

Purpose of the Study:

• To highlight the importance of rational laboratory use in diagnostics.
• To educate clinicians on factors influencing laboratory test results.
• To emphasize the need for understanding preanalytical, analytical, and biological variability.

Main Methods:

• Discussion of preanalytical factors impacting laboratory results.
• Explanation of analytical and biological variability of laboratory parameters.
• Review of critical difference and its role in longitudinal patient evaluation.
• Examination of diagnostic sensitivity and specificity in clinical context.

Main Results:

• The preanalytical phase significantly influences laboratory values due to factors affecting patients and specimens.
• Biological variability, linked to homeostatic regulation, can be high for certain parameters, affecting critical difference values.
• Lack of information on diagnostic sensitivity and specificity is a common reason for inappropriate laboratory test utilization.

Conclusions:

• Clinicians must be knowledgeable about preanalytical issues, biological variability, and critical differences for accurate interpretation.
• Understanding diagnostic sensitivity and specificity is crucial for determining a test's value in a specific clinical context.
• Adopting a rational approach to laboratory diagnostics improves test utility and clinical decision-making.