1. Department of medicine; Baerum hospital; Baerum Norway
2. Department of medicine; Østfold Hospital trust; Fredrikstad Norway
3. Department of medicine; St Olavs hospital; Trondheim Norway
4. Department of medicine; Ålesund hospital; Ålesund Norway
5. Department of anesthesiology; Østfold Hospital trust; Fredrikstad Norway
6. University of Oslo; Oslo Norway