Abstract
Objective: Principles of assessment for standardized laboratory methods in contemporary EQA programs in era harmonization Method: Publication on the ways of using control limits according to Stockholm declaration and EFLM working group for EQA acceptance limits. Discussion about bias and total error values of measurement results of standardized laboratory methods within last three years.
Results: Bias and total error values in standardized routine methods, published by different sources show significant degree of agreement. Best situation we can see in case of serum electrolytes measurement except phosphates in some manufacturers.
Maximal observed differences between routine methods are in serum enzyme and in lipid (HDL, LDL) measurements. The lack of implementation of standardization is main reason for this situation.
Another reason for too big differences may be different analytical quality of routine methods as we can see in case of HbA1c results. Introduced results show clear unsuitability for using "peer group" values for assessment in EQA programs.
Discussion: EQA programs are not only tools for reaching accreditation documentation or tool of business politics of manufacturers. They are namely tool for objective and valid determination of analytical quality indicators values for standardized methods and analytes.
Basic condition for use of EQA programs as integral part of harmonization process is maximal elimination of using "peer group" as reference values. Real reference values should be generally used for this purpose.