1. Department of Nursing Science, University of Oslo, PB 1018, Blindern, 0315 Oslo, Norway
2. Faculty of Health and Social Studies, University College of Southeast Norway, Porsgrunn, Postboks 235, 3603 Kongsberg, Norway
3. Centre for the Study of Professions, Oslo and Akershus University College of Applied Sciences, Postboks 4, St. Olavs Plass, 0130 Oslo, Norway