1. Analytical Quality Commission, Spanish Society of Laboratory Medicine (SEQCML) , Barcelona , Spain
2. Department of Laboratory Medicine , Hospital Universitario La Paz , Madrid , Spain
3. Undergraduate Teaching, School of Medicine, University of Dundee , Dundee , Scotland
4. Department of Medical Biochemistry and Pharmacology , Norwegian Organization for Quality Improvement of Laboratory Examinations (NOKLUS), Haukeland University Hospital , Bergen , Norway
5. Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan , Milan , Italy
6. Department of Laboratory Medicine , Hospital Royo Villanova , Zaragoza , Spain
7. Servizio Medicina di Laboratorio, Ospedale San Raffaele , Milan , Italy
8. Department of Medical Biochemistry Atasehir , School of Medicine, Acibadem Mehmet Ali Aydınlar University , Istanbul , Turkey
9. Clinical Biochemistry Department , Metropolitan North Clinical Laboratory (LUMN), Germans Trias i Pujol University Hospital , Barcelona , Spain
10. Department of Clinical Biochemistry , Hospital Universitario Badalona , Badalona , Spain
11. Department of Medical Biochemistry and Pharmacology , Haukeland University Hospital , Bergen , Norway