1. Department of Research and Development , Division of Emergencies and Critical Care, Oslo University Hospital , Oslo , Norway
2. Department of Psychology , University of Oslo , Forskningsveien 3a , Oslo , 0373, Norway
3. Department of Obstetrics and Gynecology , Akershus University Hospital , Lørenskog , Norway
4. Faculty of Medicine , Oslo Centre of Biostatistics and Epidemiology, University of Oslo , Oslo , Norway
5. Department of Chronic Diseases and Ageing , National Institute of Public Health , Oslo , Norway
6. Institute of Clinical Medicine, Campus Ahus, University of Oslo , Lørenskog , Norway