1 – Scheme overview

This external quality assessment scheme is designed to assess different methods used to screen for circulating anticoagulants. The scheme covers the main reagents available on the market.

Statistical reports are sent with supporting comments from the expert clinical biologists who coordinate the scheme.

Participating labs can choose to be assessed for all the analytes of this scheme, or simply a subset of analytes of interest.

2 – Assessment frequency

Number of investigations per year: 4
Number of control samples per investigation: 2
Number of samples per year : 8

3 – List of analytes assessed 

• ROSNER index
• Sensitive aPTT/Less Sensitive aPTT Normalized Ratio
• Russell test (screening and confirmation)
• Mixing Test on dRVVT
• Staclot LA
• Hemosil Silica Clotting Time (Screening and Confirmation)

The evaluation of test results is both quantitative and qualitative (negative, positive, equivocal).

4 – Description of the control samples

Lyophilized human control plasma (citrate) (samples to be resuspended in 1 mL of distilled water).

The sample volume provided for this EQA is 1 mL. Labs wishing to assess all their tests are therefore advised to order an additional kit.