1. King's College London, Cicely Saunders Institute, Bessemer Road, London, SE5 9PJ, UK
2. London North West University Healthcare NHS Trust, Watford Road, Harrow HA1 3UJ, UK
3. Palliative and End of Life Care Research Group, Population Health Sciences, Bristol Medical School, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK