1. Department of Epidemiology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
2. Department of Psychiatry; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
3. Department of General Practice; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
4. Department of Geriatrics; University Medical Center Groningen; Groningen The Netherlands