title: Association of Red Blood Cell Transfusion, Anemia, and Necrotizing Enterocolitis in Very Low-Birth-Weight Infants.
abstract: OBJECTIVE
  Data regarding the contribution of red blood cell (RBC) transfusion and anemia to necrotizing enterocolitis (NEC) are conflicting. These associations have not been prospectively evaluated, accounting for repeated, time-varying exposures.
  
  
  OBJECTIVE
  To determine the relationship between RBC transfusion, severe anemia, and NEC.
  
  
  METHODS
  In a secondary, prospective, multicenter observational cohort study from January 2010 to February 2014, very low-birth-weight (VLBW, ≤1500 g) infants, within 5 days of birth, were enrolled at 3 level III neonatal intensive care units in Atlanta, Georgia. Two hospitals were academically affiliated and 1 was a community hospital. Infants received follow-up until 90 days, hospital discharge, transfer to a non-study-affiliated hospital, or death (whichever came first). Multivariable competing-risks Cox regression was used, including adjustment for birth weight, center, breastfeeding, illness severity, and duration of initial antibiotic treatment, to evaluate the association between RBC transfusion, severe anemia, and NEC.
  
  
  METHODS
  The primary exposure was RBC transfusion. The secondary exposure was severe anemia, defined a priori as a hemoglobin level of 8 g/dL or less. Both exposures were evaluated as time-varying covariates at weekly intervals.
  
  
  METHODS
  Necrotizing enterocolitis, defined as Bell stage 2 or greater by preplanned adjudication. Mortality was evaluated as a competing risk.
  
  
  RESULTS
  Of 600 VLBW infants enrolled, 598 were evaluated. Forty-four (7.4%) infants developed NEC. Thirty-two (5.4%) infants died (all cause). Fifty-three percent of infants (319) received a total of 1430 RBC transfusion exposures. The unadjusted cumulative incidence of NEC at week 8 among RBC transfusion-exposed infants was 9.9% (95% CI, 6.9%-14.2%) vs 4.6% (95% CI, 2.6%-8.0%) among those who were unexposed. In multivariable analysis, RBC transfusion in a given week was not significantly related to the rate of NEC (adjusted cause-specific hazard ratio, 0.44 [95% CI, 0.17-1.12]; P = .09). Based on evaluation of 4565 longitudinal measurements of hemoglobin (median, 7 per infant), the rate of NEC was significantly increased among VLBW infants with severe anemia in a given week compared with those who did not have severe anemia (adjusted cause-specific hazard ratio, 5.99 [95% CI, 2.00-18.0]; P = .001).
  
  
  CONCLUSIONS
  Among VLBW infants, severe anemia, but not RBC transfusion, was associated with an increased risk of NEC. Further studies are needed to evaluate whether preventing severe anemia is more important than minimizing RBC transfusion.
authors.affiliation: Department of Pediatrics, Emory University School of Medicine & Children's Healthcare of Atlanta, Atlanta, Georgia.
authors.forename: Ravi M
authors.initials: RM
authors.lastname: Patel
authors.affiliation: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, Georgia.
authors.forename: Andrea
authors.initials: A
authors.lastname: Knezevic
authors.affiliation: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, Georgia.
authors.forename: Neeta
authors.initials: N
authors.lastname: Shenvi
authors.affiliation: Department of Neonatology, Northside Hospital, Atlanta, Georgia.
authors.forename: Michael
authors.initials: M
authors.lastname: Hinkes
authors.affiliation: Department of Pediatrics, Emory University School of Medicine & Children's Healthcare of Atlanta, Atlanta, Georgia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Keene
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia5Center for Transfusion and Cellular Therapies, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: John D
authors.initials: JD
authors.lastname: Roback
authors.affiliation: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, Georgia.
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Easley
authors.affiliation: Department of Pediatrics, Emory University School of Medicine & Children's Healthcare of Atlanta, Atlanta, Georgia4Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia5Center for Transfusion and Cellular T.
authors.forename: Cassandra D
authors.initials: CD
authors.lastname: Josephson
mesh_terms: D000740:Anemia / Q000097:blood / Q000150:complications* / Q000628:therapy; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001724:Birth Weight; D020345:Enterocolitis, Necrotizing / Q000453:epidemiology / Q000209:etiology*; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D005260:Female; D005845:Georgia; D005865:Gestational Age; D006441:Hemoglobin A / Q000032:analysis; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D008297:Male; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents; D006441:Hemoglobin A