On Hierarchical Composite Endpoints in Pediatric Cancer Supportive Care: Illustrative Examples From Two Multi‐Center Phase‐III Randomized Clinical Trials

Pediatric supportive care clinical trials often involve multiple clinically important outcomes, complicating trial interpretation. Hierarchical composite endpoints (HCEs) provide a framework to integrate key outcomes according to clinical importance. We performed post hoc analyses using HCE in two randomized trials conducted by the Children's Oncology Group. We found that HCE can be more sensitive overall endpoints for detecting treatment benefit as well as found that HCE can support harmonized trial conclusions in the presence of intervention benefits and harms. These analyses illustrate the potential of HCE to improve the interpretability of complex pediatric supportive care trials and support consideration of their prospective use.