1. Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus) , Haraldsplass Deaconess Hospital , Bergen , Norway
2. General Practice Research Unit (AFE), Department of General Practice, Institute of Health and Society , University of Oslo , Oslo , Norway
3. Institute of Clinical Medicine, Faculty of Medicine , University of Oslo , Oslo , Norway
4. Department of Endocrinology, Morbid Obesity and Preventive Medicine , Oslo University Hospital , Oslo , Norway
5. Department of Medicine , Stavanger University Hospital , Stavanger , Norway
6. Department of Global Public Health and Primary Care , University of Bergen , Bergen , Norway
7. Department of Medical Biochemistry and Pharmacology , Haukeland University Hospital , Bergen , Norway