1. Department of Population Medicine at Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts
2. Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
3. The Danish Clinical Quality Program, National Clinical Registries, Aarhus, Denmark
4. Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
5. Clinical Excellence Research Center, Stanford University, Stanford, California
6. Department of Epidemiology and Population Health, Stanford University, Stanford, California
7. Department of Neurology and Neurological Sciences, Stanford University, Stanford, California