1. Department of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), 7030 Trondheim, Norway
2. Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), 7030 Trondheim, Norway
3. Clinical Research Unit Central Norway, St. Olavs Hospital, 7030 Trondheim, Norway
4. Department of Family Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, CA 91803, USA