1. Department of General Practice and Elderly MedicineUniversity Medical Centre Groningen, University of GroningenGroningen The Netherlands
2. Department of UrologyIsala ClinicsZwolle The Netherlands
3. Department of UrologyRijnstate HospitalArnhem The Netherlands
4. Department of Public and Occupational Health, Amsterdam Public Health Research Institute, Amsterdam UMCVrije Universiteit AmsterdamAmsterdam The Netherlands