[1] University of Texas,Department of Palliative Care, Rehabilitation and Integrative Medicine, Unit 414
[2] MD Anderson Cancer Center,Department of Palliative Care
[3] King Hussein Cancer Center,Department of Medical Oncology
[4] Barretos Cancer Hospital,Departamento Medicina Interna, Escuela de Medicina
[5] Pontificia Universidad Católica de Chile,Department of Palliative Care
[6] Tata Memorial Center,Department of Biostatistics
[7] MD Anderson Cancer Center,undefined