Data collection and statistical analyses
Two trained pediatric oncology physicians (DJB and CIW) abstracted data from the patients’ medical records using a standardized data collection form in REDCap, an electronic data management platform. The form was first pilot-tested by the two clinicians and modified to ensure the data of interest was collected. To ensure consistency, the two clinicians met before abstracting data and throughout data collection to reach consensus on definitions. Each clinician also independently reviewed two records that had been abstracted by the other and no discrepancies were found. Descriptive statistics were used to summarize patient demographics, clinical characteristics, toxicities, and outcomes, including frequencies and proportions for categorical variables and medians and ranges for continuous variables. Statistical analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC).