1. Palliative and End of Life Care Research Group, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
2. School of Dentistry, Cardiff University, Cardiff, UK
3. Marie Curie Research Centre, Cardiff University, Cardiff, UK
4. PRIME Centre, Division of Population Medicine, Cardiff University, Cardiff, UK
5. Wales Cancer Research Centre, Cardiff, UK
6. Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
7. Keele University, Keele, UK