1 Department of Medical Psychology, Academic Medical Centre, University of Amsterdam, The Netherlands. Electronic address: e.m.smets@ams.uva.nl.
2 Faculty of Medicine and Health Sciences, Department of Family Medicine and Primary Health Care, Ghent University, Ghent, Belgium.
3 Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Institute for Medicine and Public Health, Vanderbilt University, Nashville, TN, USA.
4 Division of General Internal Medicine and Geriatrics, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.