1. Department of Endocrinology (T.L.N., C.H., K.W., K.B., M.A.), Odense University Hospital, 5250 Odense SV, Denmark
2. Departments of Norwegian Quality Improvement of Primary Care Laboratories (P.H.P.), Division for General Practice, University of Bergen, 5020 Bergen, Norway
3. Departments of Hormone Laboratory (E.H.), Aker University Hospital, 0514 Oslo, Norway
4. Department of Informatics and Mathematical Modeling (R.L.), Technical University of Denmark, Copenhagen, 2800 Kongens Lyngby, Denmark