1. School of Health, Business and Natural Sciences, University of Akureyri, 600 Akureyri, Iceland
2. Health Care Institution of North Iceland, 580 Siglufjordur, Iceland
3. Akureyri Hospital, 600 Akureyri, Iceland
4. Department of Health and Caring Sciences, Western Norway University of Applied Sciences, 5063 Bergen, Norway
5. Institute of Psychology, University of Copenhagen, 1017 Copenhagen K, Denmark
6. Australian Centre for Behavioral Research in Diabetes, Melbourne, VIC 3053, Australia