1. Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
2. Department of Medicine, Brigham and Women's Hospital, Divisions of Preventive Medicine and Aging, Harvard Medical School, Boston, MA, USA
3. Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA
4. Department of Ambulatory Care and Prevention, Harvard Medical School, Boston, MA, USA