Developing a risk-based composite neurologic outcome for a trial of hydroxyurea in young children with sickle cell disease.

This set of studies provides the rationale, justification, and validation for the use of a weighted composite outcome and confirms the need for the phase III HU Prevent study. Surveys of investigators in multi-center studies can provide the basis of clinically meaningful outcomes that foster the translation of study results into practice while increasing the efficiency of a study.