1. Department of Pediatric Medicine, Division of Palliative and End-of-Life Care, St. Jude Children's Research Hospital, Memphis, Tennessee.
2. Department of Bioinformatics and Biostatistics, School of Public Health and Information Sciences, University of Louisville, Louisville, Kentucky.
3. Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee.
4. Department of Nursing Research, Children's National Medical Center, Washington, D.C.
5. Department of Pediatrics, George Washington University, Washington, D.C.