1. Neurochemistry LaboratoryDepartment of Clinical ChemistryAmsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit AmsterdamAmsterdamThe Netherlands
2. Department of Neurology, Alzheimer Center, Amsterdam Neuroscience, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
3. Epidemiology and Biostatistics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
4. Roche Diagnostics GmbHPenzbergGermany
5. Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
6. Department of Geriatric MedicineNoordwest Hospital GroupAlkmaarThe Netherlands
7. Department of NeurologyTergooi HospitalHilversumThe Netherlands
8. Department of NeurologyAdmiraal De Ruyter HospitalGoesThe Netherlands
9. Department of GeriatricsJeroen Bosch Hospital's‐HertogenboschThe Netherlands
10. Department of Family Medicine and Elderly Care Medicine, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
11. Department of NeurologyElisabeth Tweesteden Hospital (ETZ)TilburgThe Netherlands
12. Department of NeurologySpaarne GasthuisHaarlemThe Netherlands
13. Department of NeurologyMedisch Centrum LeeuwardenLeeuwardenThe Netherlands