1. Health Economics Research Group; Brunel University London; London UK
2. Sheila Sherlock Liver Unit and UCL Institute for Liver and Digestive Health; The Royal Free Hospital and UCL; London UK
3. Division of Surgery; Royal Free Campus; UCL Medical School; London UK
4. Cochrane Dementia and Cognitive Improvement Group; Nuffield Department of Medicine; Oxford University; Oxford UK
5. Laiko Hospital; University Department of Gastroenterology; Athens Greece