1 Institute of Nursing and Health Sciences, Faculty of Health and Social Sciences, University College of Southeast Norway, Norway.
2 NIVEL (Netherlands Institute for Health Services Research), Utrecht, the Netherlands; Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, the Netherlands; Science Centre Health and Technology, Faculty of Health Sciences, University College of Southeast Norway, Drammen, Norway.
3 Department of Behavioural Sciences in Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway.
4 Department of Behavioural Sciences in Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway. Electronic address: anneli.mellblom@medisin.uio.no.