There has been a significant expansion in the number of low-level and midlevel neonatal intensive care units (NICUs) in recent decades. Infants with necrotizing enterocolitis represent a high-risk subgroup of the very low-birth-weight (VLBW) (<1500 g) population that would benefit from focused regionalization.OBJECTIVES
To describe the current trend toward deregionalization and to test the hypothesis that infants with necrotizing enterocolitis represent a particularly high-risk subgroup of the VLBW population that would benefit from early identification, increased intensity of early management, and possible targeted triage to tertiary hospitals.DESIGN, SETTING, AND PARTICIPANTS
A retrospective cohort study was conducted of NICUs in California. We used data collected by the California Perinatal Quality Care Collaborative from 2005 to 2011 to assess mortality rates among a population-based sample of 30 566 VLBW infants, 1879 with necrotizing enterocolitis, according to the level of care and VLBW case volume at the hospital of birth.EXPOSURES
Level and volume of neonatal intensive care at the hospital of birth.MAIN OUTCOMES AND MEASURES
There was a persistent trend toward deregionalization during the study period and mortality rates varied according to the level of care. High-level, high-volume (level IIIB with >100 VLBW cases per year and level IIIC) hospitals achieved the lowest risk-adjusted mortality. Infants with necrotizing enterocolitis born into midlevel hospitals (low-volume level IIIB and level IIIA NICUs) had odds of death ranging from 1.42 (95% CI, 1.08-1.87) to 1.51 (95% CI, 1.05-2.15, respectively). In the final year of the study, just 28.6% of the infants with necrotizing enterocolitis were born into high-level, high-volume hospitals. For infants born into lower level centers, transfer to a higher level of care frequently occurred well into the third week of life.CONCLUSIONS AND RELEVANCE
These findings represent an immediate opportunity for local quality improvement initiatives and potential impetus for the regionalization of important NICU resources.