1 Department of Public Health and Primary Care, Leiden University Medical Centre, Hippocratespad 21 Post zone V0-P, PO Box 9600, Leiden, RC, 2300, The Netherlands. a.h.van_dalen@lumc.nl.
2 Department of Public Health and Primary Care, Leiden University Medical Centre, Hippocratespad 21 Post zone V0-P, PO Box 9600, Leiden, RC, 2300, The Netherlands. m.j.c.pieper@lumc.nl.
3 Department of General Practice & Elderly Care Medicine, VU University Medical Centre Amsterdam, van der Boechorststraat 7, Amsterdam, BT, 1081, The Netherlands. m.j.c.pieper@lumc.nl.
4 Department of Public Health and Primary Care, Leiden University Medical Centre, Hippocratespad 21 Post zone V0-P, PO Box 9600, Leiden, RC, 2300, The Netherlands. m.w.m.de_waal@lumc.nl.
5 Malteser Hospital Bonn/Rhein-Sieg, Centre of Geriatric Medicine, Academic Hospital University of Bonn, Von-Hompesch-Straße 1, Bonn, 53123, Germany. albert.lukas@malteser.org.
6 Department of Public Health and Primary Care, Centre for Elderly and Nursing Home Medicine, University of Bergen, Bergen, Norway. bettina.husebo@igs.uib.no.
7 Stavanger University Hospital, Bergen, Norway. bettina.husebo@igs.uib.no.
8 Department of Public Health and Primary Care, Leiden University Medical Centre, Hippocratespad 21 Post zone V0-P, PO Box 9600, Leiden, RC, 2300, The Netherlands. w.p.achterberg@lumc.nl.