[1] Radboud Univ Nijmegen Med Ctr, Ctr Family Med Geriatr Care & Publ Hlth, Dept Primary & Community Care, NL-6500 HB Nijmegen, Netherlands
[2] Vrije Univ Amsterdam Med Ctr, Dept Gen Practice & Elderly Care Med, EMGO Inst Hlth & Care Res, NL-1007 MB Amsterdam, Netherlands
[3] Dutch Inst Rat Use Med, NL-3502 TB Utrecht, Netherlands
[4] Univ Groningen, Univ Med Ctr Groningen, Dept Gen Practice, HPC FA21, NL-9700 AD Groningen, Netherlands