Children undergoing stem cell transplants are at risk for delirium, a temporary change in thinking and behavior. This study will define delirium rates, risk factors, and outcomes. Our eventual goal is to reduce delirium in this population.

Delirium -- defined as an acute change in awareness and cognition that occurs in the setting of an underlying illness -- is a common complication of hematopoietic stem cell transplantation (HSCT) in adults, with associated morbidity and mortality. This has never been studied in children, where risk factors may vary substantially from adults. The objectives of this study are: to define the epidemiology of delirium, and measure its effect on outcomes.

This prospective longitudinal cohort study will prospectively establish the incidence of delirium in 1000 children in the peri-transplant period, and identify modifiable risk factors that predispose to delirium development. This study will also define the effect of delirium on important clinical outcomes, including neurocognitive function. This study will be executed by a research consortium of five leading pediatric oncologic transplant centers in North America, in collaboration with the leading pediatric delirium research group in the United States.

This innovative proposal will leverage the combined experience of the pediatric delirium and HSCT teams to expand urgently needed delirium research into a unique and unstudied population. By reducing delirium rates, outcomes after pediatric HSCT can be optimized.

Inclusion Criteria:

• Age 0-21 years old
• Admitted for purpose of stem cell transplant

Exclusion Criteria:

• Age >21 years old
• Admitted for reason other than stem cell transplant (example: late post-transplant complications).

Subjects will include all patients admitted to the five participating pediatric stem cell transplant sites for the purpose of HSCT during the study period. Enrollment goal is 1000 subjects overall, and 240 subjects for neurocognitive testing. Subjects will be seriously ill. Every patient admitted for HSCT will be eligible for inclusion, unless they are >21 years old. Subjects will be enrolled regardless of gender, race, or ethnicity. No subgroups will be excluded, as delirium likely affects children of all ages and developmental trajectories, with no predilection based on gender, race, or ethnicity.

De-identified individual participant data will be shared via NIH-approved repositories within 12 months after publication of primary results. The sharing of unpublished information may be subject to confidentiality issues and will need to be discussed with the appropriate institutions before any request is granted. Access will be granted to qualified researchers with a methodologically sound proposal and appropriate agreements, for academic research, meta-analyses, and other approved studies.

De-identified IPD will be available no later than 12 months after publication of the primary results and for at least 5 years thereafter.

Access will be granted to qualified researchers with a methodologically sound proposal. Researchers must agree to a data use agreement, and requests will be reviewed by the study team and the Data Coordinating Center.