1 Clinical Effectiveness Unit, Royal College of Surgeons of England, London, UK; Hull York Medical School, Hull, UK. Electronic address: [email protected].
2 Clinical Effectiveness Unit, Royal College of Surgeons of England, London, UK; Hull York Medical School, Hull, UK.
3 Lyme Building, Royal Stoke University Hospital, Stoke-on-Trent, UK.
4 Division of Vascular Surgery, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
5 Cambridge Vascular Unit, Cambridge University Hospitals NHS Trust, Cambridge, UK.