[1
]
Netherlands Institute for Health Services Research (NIVEL), Utrecht, The Netherlands.
Electronic address: i.vanderheide@nivel.nl.
[2
]
Netherlands Institute for Health Services Research (NIVEL), Utrecht, The Netherlands.
[3
]
Centre for Socio-Economic Research on Ageing, National Institute of Health and Science
on Ageing (INRCA), Ancona, Italy.
[4
]
Technical University of Berlin, Berlin, Germany.
[5
]
University of Eastern Finland, Kuopio, Finland.
[6
]
Netherlands Institute for Health Services Research (NIVEL), Utrecht, The Netherlands;
VU University, Amsterdam, The Netherlands.