1. University of Pennsylvania, Department of Psychology, Philadelphia, Pennsylvania.
2. Children's Hospital of Philadelphia, Center for Childhood Cancer Research, Philadelphia, Pennsylvania.
3. University of Pennsylvania, Department of Pediatrics, Philadelphia, Pennsylvania.
4. University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania.
5. Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
6. University of Cincinnati, Department of Pediatrics, Cincinnati, Ohio.