1. George Washington University, Washington, DC, USA;
2. University of Virginia, Charlottesville, Virginia, USA;
3. National Institutes of Health, Bioethics, Clinical Center, Bethesda, Maryland, USA;
4. Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
5. Memorial Sloan Kettering Cancer Center, New York, New York, USA;
6. School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania, USA