1. Faculty of Health Studies, Sogn og Fjordane University College, Førde, Norway
2. Centre of Health Research, Førde Hospital Trust, Førde, Norway
3. Department of Research and Development, Haukeland University Hospital, Bergen, Norway
4. Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway
5. Department of Surgery, Voss Hospital, Helse Bergen Health Trust, Voss, Norway