The Vitamin K External Quality Assurance Scheme (KEQAS)
KEQAS is an international scheme that monitors and reports on the accuracy of vitamin K1 (phylloquinone) analysis. KEQAS is overseen by a steering committee.
KEQAS Steering Committee members
Dr Dominic Harrington (Scheme Director)
Principal Clinical Scientist
Human Nutristasis Unit
Centre for Haemostasis and Thrombosis
Guy's and St. Thomas' Foundation Trust
UK
domonic.harrington@gstt.nhs.uk
Dr Martin Shearer (Chairman)
Principal Clinical Scientist
Centre for Haemostasis and Thrombosis
Guy's and St. Thomas' Foundation Trust
UK
martin.shearer@gstt.nhs.uk
Dr Leon Schurgers (Scientific Director)
Senior Scientist
Dept. of Biochemistry
University of Maastricht
The Netherlands
l.schurgers@bioch.unimaas.nl
Mr David Card MSc (Scheme Manager)
Centre for Haemostasis and Thrombosis
Guy's and St. Thomas' Foundation Trust
UK
david.card@gstt.nhs.uk
Mr Tony Sunner (Scheme Quality Manager)
Centre for Haemostasis and Thrombosis
Guy's and St. Thomas' Foundation Trust
UK
tony.sunner@gstt.nhs.uk
Background
At the 10th meeting of the European Fat-soluble Vitamins Group in 1996, it was agreed that a quality assurance scheme for the determination of vitamin K1 should be initiated since self “in-house” assessment of laboratory performance makes it difficult to identify systematic errors. It was decided that participation in an external quality assurance scheme would greatly assist the development and harmonisation of methods for vitamin K analyses and their application to nutritional and clinical studies.
Members receive three batches of three blind samples each year and are required to analyse them during specific periods over the course of the year. When results are returned they are subjected to statistical analysis including an outliers test and a Z scoring system. The target for accuracy of analysis is currently set at 20 % from the All Laboratories Trimmed Mean (ALTM) and this is the standard by which results are judged good, acceptable, questionable or unacceptable. Members then receive comprehensive reports detailing their performance.
KEQAS is now a member of UKNEQAS and is CPA (EQA) accredited. For more information please vist the UKNEQAS website.
Join KEQAS
Please email david.card@gstt.nhs.uk including your contact name and address to which samples should be sent.