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A Decade of Improvement in Neonatal Intensive Care: How Do We Continue the Momentum?

The work by Horbar et al1 looks into the progress of neonatal care in the United States between 2005 and 2014. Using the data set from the Vermont Oxford Network, the study found that among 756 US neonatal intensive care units (NICUs) in 2014, more than 98% had achieved the risk-adjusted rate of mortality of the best 10% of units in 2005; more than 90% had achieved this rate of late infection; and 40% to 60% had achieved the rate of the best 10% of units in 2005 for necrotizing enterocolitis, severe intraventricular hemorrhage, or severe retinopathy of prematurity. Such longitudinal improvement in outcomes from this group of hospitals provides reassurance for our ability to meaningfully improve outcomes. However, the study also emphasizes the barriers—persistent variation between hospitals, volatility of rare outcomes, and the need to explore population-based outcomes of perinatal care—to continue the highlighted improvements. The first and most obvious issue is the persistent variation between highand low-performing hospitals in each of these outcomes (Figure 1 in Horbar et al1). These differences are not insignificant: a 2% absolute difference in mortality (20% relative difference), a 14.4% difference in bronchopulmonary dysplasia (BPD) (66% relative difference), a 6.6% difference in late infection (94% relative difference), a 3.2% difference in necrotizing enterocolitis (86% relative difference), a 1.6% difference in severe intraventricular hemorrhage (22% relative difference), and a 4.4% difference in severe retinopathy of prematurity (105% relative difference). Also, BPD did not show the same improvement in outcomes as the other 5 measures examined in the study. What is driving these observations? Horbar et al1 identified 3 potential areas for the failure of BPD to improve in the Vermont Oxford Network collaborative: less effective quality improvement collaborations, less reliable implementation of these initiatives, or an imprecise definition of BPD. The fact that there have been 3 cluster randomized studies to improve BPD,2,3 which has a minimal effect on hospital BPD rates, suggests that the identification of such improvement initiatives, and the implementation of potential improvement projects, should be viewed more creatively through the needs of an individual hospital based on the specific elements of care quality provided at these hospitals.4 However, we also know that patient case-mix and other factors such as community and social determinants of health may differ strongly within the large number of NICUs in the United States. Whether a group of quality improvement initiatives would work across hospitals of different case-mix and communities is not shown. Bronchopulmonary dysplasia also has a complex multimodal conceptual model in which numerous unrelated factors may result in an infant presenting with clinical signs of BPD, including ventilator injury, abnormal lung development, infection, or nutritional deficits. More precise definitions of BPD may allow for the precise targeting of different drivers for elevated rates of BPD in certain NICUs, which likely differ from the next NICU. The second aspect of care that the data do not address is the interyear volatility of outcomes within a specific hospital. Given the rarity of each of these outcomes, many hospitals are only 1 to 2 extra events from experiencing a “spike” in outcomes. This noise makes it difficult for a hospital in real time to determine whether a change in outcomes represents a true trend or random fluctuation in outcomes. The use of statistical techniques presented by Horbar et al,1 such as random effects shrinkage, are one method. However, since this technique uses the number of events or hospital volume to determine the amount of shrinkage to the mean rate in the population, this technique may provide unclear results when there is a volume-outcome association,5 as has been shown in neonatal care.6-8 The lack of validated statistical methods to assess hospitals with few events per year is an additional barrier to improving care. Finally, there is a growing realization that neonatal care does not exist in a vacuum, but rather in a larger structure of perinatal care in a specific region or state. This care spans from the first time a pregnant woman seeks health care to the final place where a very low-birth-weight infant is discharged. Neonatal care has typically been examined within a silo centered on the NICU, with less attention placed on the relationship between antepartum and intrapartum care of the mother and the other potential sites of newborn care in a geographic area. Few measures assess these outcomes at the regional level. However, with the growth of accountable care organizations and other population-based assessments of health, understanding how individual NICUs interface with these larger structures of health care to result in observed variations in outcomes will continue to grow in importance. Horbar et al1 provide important and thought-provoking information about a field’s ability to improve overall outcomes and barriers to continued improvement, including persistent variation between hospitals. There is a need for further research on the underlying pathophysiology for these outcomes, but also for consideration of the patient, community, and hospital-level factors that may contribute to the variation in outcomes observed between hospitals and the variation in Related article Opinion