Affiliation: | 1. Division of Oncology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania;2. Division of Pulmonary Medicine, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania;3. CHOP‐Westat Biostatistics and Data Management Core, Philadelphia, Pennsylvania;4. Division of Paediatric Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada;5. Division of Pulmonary Medicine, Department of Pediatrics, The Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania |