1. Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
2. Research Unit of General Practice, Department of Public Health, University of Southern Denmark, Odense, Denmark
3. Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
4. Department of Medical, Herlev and Gentofte Hospital, Herlev, Denmark
5. Clinical Nursing, Department of Intensive Care, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
6. Section of Health Services Research, Department of Public Health, University of Copenhagen, Copenhagen, Denmark