1. Department of General Practice, Institute of Health and Society, University of Oslo, Oslo, Norway;
2. Department of Primary Health Care, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden;
3. School of Medicine, University of Tampere, Tampere, Finland;
4. Centre of General Practice, Pirkanmaa Hospital District, Pirkanmaa, Finland;
5. Grafarvogur Primary Care Centre, Reykjavik, Iceland;
6. Research Unit for General Practice, Aarhus University, Aarhus, Denmark