1 Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands; Department of Primary Care and Public Health Sciences, Division of Health and Social Care Research, King's College London, Guy's, AH 3.2, SE1 1UL London, United Kingdom. Electronic address: r.koleva-kolarova@umcg.nl.
2 Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands. Electronic address: z.zhan01@umcg.nl.
3 Department of Radiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands. Electronic address: m.j.w.greuter@umcg.nl.
4 Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands; National Institute for Public Health and the Environment (RIVM), Centre for Nutrition, Prevention and Health Services Research, PO Box 1, 3720BA Bilthoven, The Netherlands. Electronic address: t.l.feenstra@umcg.nl.
5 Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands. Electronic address: g.h.de.bock@umcg.nl.