1. Palliative Care Unit, Fundación Jiménez Díaz University Hospital, Madrid, Spain.
2. Health Research Institute of the Jimenez Diaz Foundation, Madrid, Spain.
3. Internal Medicine Department, Severo Ochoa University Hospital, Madrid, Spain.
4. HLA Moncloa Universitary Hospital, Madrid, Spain.
5. Palliative Care Unit, Beata María Ana de Hermanas Hospitalarias Hospital, Madrid, Spain.