1. The Norwegian Quality Improvement of Laboratory Examinations (Noklus) , Haraldsplass Deaconess Hospital , Box 6165 , N-5892 Bergen , Norway , Phone: +4755979503, Fax: +4755979510
2. The Norwegian Quality Improvement of Laboratory Examinations (Noklus) , Haraldsplass Deaconess Hospital , Bergen , Norway
3. Department of Public Health and Primary Health Care , Faculty of Medicine and Dentistry , University of Bergen , Bergen , Norway