Analytical performance specifications for EQA schemes - need for harmonisation.

Area of Science:

• Laboratory Medicine
• Analytical Chemistry
• Quality Management

Background:

• External Quality Assurance (EQA) is crucial for assessing laboratory performance and inter-laboratory comparisons.
• EQA data aids professional bodies and manufacturers in post-market surveillance.
• The assessment of EQA results involves comparing individual laboratory measurements against established targets.

Purpose of the Study:

• To evaluate the current state of EQA analytical performance specifications.
• To identify factors contributing to the wide variation in EQA performance criteria.
• To discuss the implications of differing EQA specifications on laboratory quality.

Main Methods:

• Analysis of the current practices and criteria used by External Quality Assurance providers.
• Review of the Stockholm hierarchy of performance goals and its application.
• Examination of different models (e.g., state of the art, biological variation) for setting performance criteria.

Main Results:

• Significant variation persists in EQA analytical performance specifications fifteen years after the Stockholm consensus.
• Factors such as the rationale for criteria, response to failure, and clinical relevance contribute to this variation.
• Differences exist in the models used to set criteria and their application among EQA providers.

Conclusions:

• Harmonization of EQA performance specifications remains a challenge.
• EQA providers must clearly define and communicate the nature and basis of their performance specifications.
• Transparency in EQA criteria is essential for laboratory customers and quality improvement.