Analytical Performance Specifications Derived from External Quality Assessment Data: Comparison with Biological...

Area of Science:

• Laboratory Medicine
• Clinical Chemistry
• Hematology
• Hemostasis

Background:

• Analytical Performance Specifications (APSs) are crucial for medical laboratory quality management.
• Existing guidelines often show discrepancies with laboratory performance and lack concentration-dependent variability consideration.
• There's a need for APSs tailored for internal laboratory use, especially for biochemistry, hemostasis, and hematology parameters.

Purpose of the Study:

• To define internal APSs for biochemistry, hemostasis, and hematology using external quality assessment (EQA) peer group data.
• To evaluate the suitability of EQA-based APSs for intermediate precision assessment.
• To compare EQA-based APSs with biological variation (BV)-based APSs.

Main Methods:

• Estimated EQA-based allowable CV (CVallowable) from pooled EQA peer group results.
• Calculated allowable bias, expanded measurement uncertainty, and total allowable error.
• Assessed CVallowable targets using intermediate precision data and compared them with BV-based APSs.

Main Results:

• Established APSs for 110 biochemical, 23 hemostasis, and 28 hematology parameters.
• EQA-derived APSs showed agreement with observed intermediate precision for a majority of parameters (102 biochemical, 14 hemostasis, 24 hematology).
• BV-based APSs demonstrated significantly less agreement (49 biochemical, 2 hemostasis, 11 hematology) and were often overly restrictive.

Conclusions:

• EQA-derived APSs provide realistic and achievable intermediate precision targets.
• These APSs are consistent with current analytical performance.
• EQA-based APSs can effectively complement BV-based specifications for laboratory quality management.