Comparison of Thrombophilia Assay Results for the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Plasma Standard from Different External Quality Assessment Providers-for the External Quality Assurance in Thrombosis and Haemostasis Group.

External quality assessment (EQA) is used to evaluate laboratory performance in tests of hemostasis; however, some esoteric tests are performed by too few centers in any one EQA program to allow valid statistical assessment. To explore the feasibility of pooling data from several EQA providers, an exercise was carried out by the External Quality Assurance in Thrombosis and Haemostasis group, using the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee (SSC) plasma standard for thrombophilia screening assays. Six EQA providers took part in this exercise, distributing the SSC plasma standard as a "blinded" sample to participants for thrombophilia tests between November 2020 and December 2021.

Lack of grading agreement among international hemostasis external quality assessment programs.

: Laboratory quality programs rely on internal quality control and external quality assessment (EQA). EQA programs provide unknown specimens for the laboratory to test. The laboratory's result is compared with other (peer) laboratories performing the same test.

Uncertainty in measurement for 43 biochemistry, immunoassay, and hemostasis routine analytes evaluated by a method using only external quality assessment data.

Background: International organizations require from medical laboratories a quantitative statement of the uncertainty in measurement (UM) to help interpret patient results. The French accreditation body (COFRAC) recommends an approach (SH GTA 14 IQC/EQA method) using both internal quality control (IQC) and external quality assessment (EQA) data. The aim of this work was to validate an alternative way to quantify UM using only EQA results without any need for IQC data.