1. Department of Orthopaedic Surgery Lovisenberg Diaconal Hospital Oslo Norway
2. Department of Nursing Science Institute of Health and Society Faculty of Medicine University of Oslo Oslo Norway
3. School of Nursing University of California San Francisco San Francisco CA USA
4. Department of Research and Development Division of Emergencies and Critical Care Oslo University Hospital Oslo Norway
5. Department of Interdisciplinary Health Sciences Institute of Health and Society Faculty of Medicine University of Oslo Oslo Norway