1. National Primary Care Research and Development Centre, University of Manchester, UK
2. Department of Public Health and International Affairs, Norwegian Board of Health, Oslo, Norway
3. Institute of Public Health-Health Economics, University of Southern Denmark, Odense, Denmark
4. National Primary Care Research and Development Centre, York University, UK
5. R&D Department, Huddersfield Royal Infirmary, UK
6. Danish Institute for Health Services Research and Development, Copenhagen, Denmark