1. Clinical Effectiveness Unit The Royal College of Surgeons of England London UK
2. Manchester University NHS Foundation Trust Wythenshawe Hospital Wythenshawe, Manchester UK
3. Health Services Research Unit Department of Public Health & Policy London School of Hygiene & Tropical Medicine London UK
4. Department of Epidemiology and Public Health University College Cork Cork Ireland
5. Western Sussex Hospitals NHS Foundation Trust Worthing Hospital Worthing West Sussex UK
6. James Paget University Hospitals NHS Foundation Trust Gorleston, Norfolk UK
7. University of East Anglia Norwich Research Park Norwich, Norfolk UK
8. Sheffield Teaching Hospitals NHS Foundation Trust Royal Hallamshire Hospital Sheffield UK