Novel Composite Endpoints after Allogeneic Hematopoietic Cell Transplantation

With the recent development of transplant-specific composite endpoints for evaluation of allogeneic hematopoietic cell transplantation (alloHCT) outcomes, the use of these novel endpoints is growing rapidly. Combining multiple endpoints into a single endpoint, these composite endpoints appear simple and can be used as a summary measure for overall effectiveness of an intervention. However, all component endpoints may not have equal clinical significance, and an intervention may not work proportionally in the same direction for all components of a composite endpoint. This may complicate the interpretation of results, particularly if there are opposing effects of differing component endpoints. We assess the benefits and limitations of various composite endpoints used in alloHCT studies recently and propose guidelines for their use and interpretation.