1. Department of Palliative, Rehabilitation, and Integrative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
2. Seccion de Cuidados Continuos y Paliativos, Pontificia Universidad Católica de Chile, Santiago, Chile.
3. Departamento de Cuidados Paliativos, Instituto Nacional de Cancerología de Guatemala, Guatemala City, Guatemala.
4. Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.