than 36 VLBW infants; the largest FIGURE 1 Meta-analysis of adequate- and high-quality publications on VLBW infants, stratified by level of adjustment for confounding. (Reprinted with permission from Lasswell S, Barfield WD, Rochat R, Blackmon L. Perinatal regionalization for very low birth weight and very preterm infants: a meta-analysis. JAMA. 2010;304 [9]:992–1000.29) FIGURE 2 Meta-analysis of adequate- and high-quality publications on ELBW infants. (Reprinted with permission from Lasswell S, Barfield WD, Rochat R, Blackmon L. Perinatal regionalization for very low birth weight and very preterm infants: a meta-analysis. JAMA. 2010;304[9]:992–1000.29) PEDIATRICS Volume 130, Number 3, September 2012 589 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from pediatrics.aappublications.org by guest on January 13, 2015 effect on mortality was for infants born at less than 29 weeks’ gestation. Other studies assessing NICU volume suggest caution in using this measure as an effective indicator of quality of care. Rogowski and colleagues assessed the potential usefulness of NICU volume as a quality indicator among 94 110 VLBW infants entered into the Vermont Oxford Network database between 1995 and 2000 and compared NICU volume with other indicators based on hospital characteristics and patient outcomes.33 They found that although annual volume explained 9% of the variation in hospital mortality rates, other hospital characteristics explained another 7%. They suggested that direct measures based on patient outcomes are more useful quality indicators than volume for the purpose of selective referral. Several studies assessed the effects of level of care, patient volume, and racial disparities on mortality of VLBW infants based on births in minorityserving hospitals. Morales34 and Howell35 evaluated mortality of VLBW infants born in minority-serving hospitals. In both studies, neonatal level of care and patient volume were each independently associated with mortality, suggesting that delivery of all VLBW infants at high-volume hospitals would reduce black-white disparities in VLBW mortality rates. Rogowski and colleagues further suggest that the quality of care in poor-outcome hospitals could be improved through collaborative quality improvement, and evidence-based selective referral.36 Several studies have compared the short-term outcome of VLBW infants born in centers with level III units (inborn) compared with those born at lower level centers and soon transferred to a higher level (level III or children’s hospital; outborn). Many of these studies are retrospective and may be subject to selection bias because infants who were transferred most likely had the highest chance of survival and thus gave the impression of lower mortality.24 In a secondary analysis of a randomized placebo-controlled study of preemptive morphine analgesia on neonatal outcomes, Palmer et al compared neonatal mortality as related to place of birth for 894 infants who were born at 23 to 32 weeks’ gestation. Outborn babies were more likely to have severe intraventricular hemorrhage (P = .0005), and this increased risk persisted after controlling for severity of illness. However, when adjusted for antenatal steroids, the effect of birth center was no longer significant.37 Evaluating and controlling for confounding variables and “case-mix” presents another set of challenges because these factors vary by population. For example, race and insurance status may have more of an effect on birth outcomes in the United States34–36,38 than in countries with a more homogenous population and universal national health care.39 There are also potential confounding factors for which measurement is frequently lacking, such as parental wishes regarding aggressive resuscitation of an infant. Arad et al noted that parental wishes varied by religious affiliation in their 2-hospital study. Because religious affiliation was unequally distributed between the 2 hospitals, fewer attempts at resuscitation may have been made at the level III hospital, with a result of improved survival at the level II facility.40 More comprehensive studies controlling for confounding factors are needed. Measured outcomes other than VLBW mortality (notably, fetal mortality, postdischarge mortality, and long-term physical and neurodevelopmental outcomes) may offer important information in assessing the evidence for newborn levels of care and perinatal regionalization. Studies measuring the effect of hospital level of birth on fetal FIGURE 3 Meta-analysis of adequate- and high-quality publications on very preterm infants (International Journal of Pediatric Research Naresh et al. Int J Pediatr Res 2022, 8:087 Volume 8 | Issue 1 DOI: 10.23937/2469-5769/1510087 Citation: Naresh PKC, Dhungana R, Gamboa E, Davis SF, Visick MK, et al. (2022) Newborn Resuscitation Scale Up and Retention Program Associated with Improved Neonatal Outcomes in Western Nepal. Int J Pediatr Res 8:087. doi.org/10.23937/2469-5769/1510087 Accepted: February 05, 2022: Published: February 07, 2022 Copyright: © 2022 Naresh PKC, et al. 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