1. M. Unsgaard-Tøndel, MSc, is a PhD candidate in the Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. Mailing address: Department of Public Health and General Practice, Norwegian University of Science and Technology, Faculty of Medicine, Medisinsk Teknisk Forskningssenter, 7489 Trondheim, Norway.
2. A.M. Fladmark, MSc, is Research Assistant, Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology.
3. Ø. Salvesen, MSc, is Assistant Professor, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology.
4. O. Vasseljen, PhD, is Associate Professor, Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology.