1. Roche Products Limited, Welwyn Garden City, UK
2. Clinical Outcomes Solutions, Tucson, AZ, USA
3. Clinical Outcomes Solutions, Folkestone, Kent, UK
4. Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
5. Parkinson Foundation Centre Kings College Hospital and Institute of Psychiatry, Psychology and Neuroscience, King’s College Londons, London, UK
6. Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
7. Parkinson’s Disease Research, Education and Clinical Center, Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
8. Department of Neurology, Montreal Neurological Institute, Montreal, Canada
9. Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED), Carlos III Institute of Health, Madrid, Spain