Factors That Impact Hospital-Specific Enrollment Rates for a Neonatal Clinical Trial: An Analysis of the HEAL Study.

Inconsistent enrollment among hospitals for neonatal clinical trials may lead to study populations that are not representative of the patient population in the neonatal intensive care unit. The High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial was a multisite randomized clinical trial investigating erythropoietin as a neuroprotective treatment for term infants (those born between 37 and 42 complete weeks) with hypoxic ischemic encephalopathy. Substantial variability was noted in enrollment rate by hospital. We developed survey questions across five conceptual domains to understand systems-level issues that might contribute to variation in enrollment rate by hospital. Our study found that hospitals varied in their responses across these five domains. We propose three potential reasons that we found a lack of identifiable hospital-level factors that correlated with enrollment rates: sample-size limitations, methodological concerns, and confounding factors. Future studies with a larger sample size should be considered to evaluate contributors to hospital-level variability. This will lead to more robust recruitment strategies, improved enrollment, and decreases in the waste of research resources.