1. Norwegian Centre for Telemedicine, University Hospital of North Norway, Tromsø, Norway
2. Department of Computer Science, University of Tromsø, Tromsø, Norway
3. School of Medicine, Biomedical and Health Informatics, University of Washington, Seattle, Washington, USA
4. Group Health Cooperative, Center for Health Studies, Seattle, Washington, USA
5. School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA
6. University of Oslo, Oslo, Norway