Assessing and Validating a Model of Study Completion for a Prospective Cohort of Healthy Newborns.

OBJECTIVES: To identify potentially modifiable or actionable factors related to study completion among healthy mother-infant dyads participating in prospective research. PATIENTS/METHODS: We conducted a secondary analysis of completion data from a prospective study on newborn jaundice in the first week of life at a tertiary-care hospital in Philadelphia, PA, from 2015 to 2019. Participation in the original study involved enrollment before newborn discharge and subsequent follow-up for a jaundice assessment between 2 and 6 days of life. For this study, our primary outcome was completion of all study procedures. Associations between predictor variables and the outcome were assessed using bivariate and multivariable analyses. We fit a predictive model of study completion using logistic regression and validated the model using 5-fold cross-validation. RESULTS: Of 501 mother-infant dyads enrolled in the original study, 304 completed the study. Median maternal age was 28 years and 81.8% of mothers delivered via vaginal birth. Study completion was associated with colocation of the study visit with the initial well-child visit (adjusted odds ratio [aOR], 2.99, 95% confidence interval [CI], 2.01-4.46) and provision of an alternate phone number by the participant (aOR, 1.99; 95% CI, 1.34-2.96). The cross-validated model performed similarly to our final predictive model and had an average area under the receiver operating characteristic curve of 0.67 (range, 0.59-0.72), with a sensitivity of 68% and specificity of 60%. CONCLUSIONS: Findings demonstrate the importance of communication and patient-centric approaches for recruitment and retention in newborn research. Future work should incorporate these approaches while continuing to evaluate study retention strategies.

Local Cues Establish and Maintain Region-Specific Phenotypes of Basal Ganglia Microglia.

Microglia play critical roles in tissue homeostasis and can also modulate neuronal function and synaptic connectivity. In contrast to astrocytes and oligodendrocytes, which arise from multiple progenitor pools, microglia arise from yolk sac progenitors and are widely considered to be equivalent throughout the CNS. However, little is known about basic properties of deep brain microglia, such as those within the basal ganglia (BG). Here, we show that microglial anatomical features, lysosome content, membrane properties, and transcriptomes differ significantly across BG nuclei. Region-specific phenotypes of BG microglia emerged during the second postnatal week and were re-established following genetic or pharmacological microglial ablation and repopulation in the adult, indicating that local cues play an ongoing role in shaping microglial diversity. These findings demonstrate that microglia in the healthy brain exhibit a spectrum of distinct functional states and provide a critical foundation for defining microglial contributions to BG circuit function.