1. Department of Clinical Chemistry, Maasstad Hospital, Rotterdam, the Netherlands
2. Department of Clinical Chemistry, Erasmus Medical Center, Rotterdam, the Netherlands
3. Department of Internal Medicine, Maasstad Hospital, Rotterdam, the Netherlands
4. Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, the Netherlands
5. Department of Clinical Chemistry, IJsselland Hospital, Capelle aan de IJssel, the Netherlands
6. Department of Central Diagnostic Laboratory, University Medical Center Utrecht, Utrecht, the Netherlands
7. Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands