1. Department of Primary Care and Population Health, UCL, London, UK.
2. Department of Community Health Sciences, St George’s, University of London, UK.
3. British Heart Foundation Glasgow Cardiovascular Research Centre, University of Glasgow, UK.
4. Department of Public Health and Primary Care, University of Cambridge, UK.
5. The Icelandic Heart Association Research Institute, Kopavogur and University of Iceland, Reykjavik, Iceland.