1. Faculty of Medicine, Department of Health Sciences, Institute of Health and Society, University of Oslo, Norway
2. Faculty of Health Science, Department of Community Medicine, The National Research Center in Complementary and Alternative Medicine, NAFKAM, UiT The Arctic University of Norway, Tromsø, Norway
3. Norwegian School of Health Sciences, Kristiania University College Oslo, Oslo, Norway
4. Faculty of Medicine, Department of General Practice, Institute of Health and Society, University of Oslo, Oslo, Norway