External analytical quality assurance for proteins

Area of Science:

• Clinical chemistry and laboratory medicine.
• Analytical chemistry and quality control.

Background:

• Achieving consistent analytical quality is crucial for reliable clinical diagnostics.
• Sharing common reference intervals requires harmonized laboratory measurements across different regions.

Purpose of the Study:

• To combine external quality assessment with standardization and quality specifications for nine serum proteins.
• To establish reliable quality specifications for sharing common reference intervals in the Nordic countries.
• To develop a control system for differentiating internal and external errors, ensuring robustness against sample interferences.

Main Methods:

• Implementation of an external quality assessment scheme.
• Utilization of a common high-quality calibrator for standardization.
• Definition of analytical quality specifications in clinical chemical terms.
• Development of a control design to separate external and internal errors.

Main Results:

• The project successfully integrated external quality assessment, standardization, and quality specifications.
• Reliable quality specifications were established for nine serum proteins, facilitating common reference intervals.
• A control design was developed to effectively distinguish between calibration and interference-related errors.

Conclusions:

• The combined approach enhances analytical quality for serum protein measurements in the Nordic region.
• The developed quality specifications and control systems are applicable for improving laboratory diagnostics.
• The project provides a framework for robust and reliable inter-laboratory comparisons and diagnostic reporting.