1. Department of Medicine, St James University Hospital NHS trust, Beckett Street, Leeds LS9 7TF;
2. Department of Medicine, St Mary's NHS Trust Hospitals, Praed Street, London W2 INY;
3. Department of Medicine, University Hospital Wales, Heath Park, Cardiff CF14, Wales;
4. Leeds University Medical School, Leeds LS2 9JT;
5. Yorkshire Deanery, Leeds LS2 9JT, UK