1 – Scheme overview

This external quality assessment scheme assesses the accuracy of unfractionated heparin and low molecular weight heparin tests.

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

2 – Assessment frequency

Number of investigations per year: 6

Number of control samples per investigation: 2 or 4

• 1 or 2 plasma samples with known levels of unfractionated heparin (UFH),
• 1 or 2 plasma samples with known levels of low molecular weight heparin (LMWH).

Number of samples per year: 20

• 10 plasma samples with known levels of unfractionated heparin (UFH),
• 10 plasmas with known levels of low lolecular weight heparin (LMWH)

4 concentration levels for standard heparin and 4 concentration levels for low molecular weight heparin are tested.

3 – List of analytes assessed 

• Unfractionated heparin (UFH)
• Low molecular weight heparin (LMWH)

4 – Description of the control samples

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