1. Research Group of Nursing and Health Sciences, Research Department Stavanger University Hospital Stavanger Norway
2. Department of Public Health, Faculty of Health Sciences University of Stavanger Stavanger Norway
3. Faculty of Health Sciences and Social Care Molde University College Molde Norway
4. Department of Medical Microbiology Stavanger University Hospital Stavanger Norway
5. Section of Biostatistics, Research Department Stavanger University Hospital Stavanger Norway