The Interhospital Transfer Network for Very Low Birth Weight Infants in the United States

Very low birth weight (VLBW) infants require specialized care in neonatal intensive care units. In the United States (U.S.), such infants frequently are transferred between hospitals. Although these neonatal transfer networks are important both economically and in terms of infant morbidity and mortality, the national-level pattern of neonatal transfers is largely unknown. Using data on 44,753 infants, 2,122 hospitals, and 9,722 inter-hospital infant transfers from 2015, we performed the largest analysis to date on the inter-hospital transfer network for VLBW infants in the U.S. We found that transfers are organized around regional communities, that, despite being largely within state boundaries, most often contain at least two hospitals in different states. Applying a spectral measure of hierarchy, we find a positive correlation between our measure and information about infants in the detected communities. Our results have a practical implication of characterizing neonatal care in the U.S. and may broadly apply to the role of hierarchical forces in organizing complex adaptive systems. Although very low birth weight (VLBW) infants, weighing less than 1,500 grams at birth, accounted for only 1.4% of all births in the United States (U.S.) in 2015, they accounted for 52% of all infant deaths [1]. These extremely fragile infants require specialized care in a neonatal intensive care unit (NICU). The creation of regional systems for perinatal care, first proposed in 1975 [2], envisioned three levels of care including NICUs, in which the hospital where a mother or infant received care was determined by the complexity of the patient?s needs. The goal was to improve outcomes for highrisk pregnant women and VLBW infants by ensuring access to high-quality, economically-efficient care for all mothers and their newborns [2]. 1 ar X iv :1 80 2. 02 85 5v 1 [ ph ys ic s. so cph ] 2 6 Ja n 20 18