title: Mortality of necrotizing enterocolitis expressed by birth weight categories.
abstract: OBJECTIVE
  Low birth weight is the most important risk factor for developing necrotizing enterocolitis (NEC). We aimed to establish birth weight-based benchmarks for in-hospital mortality in neonates with NEC.
  
  
  METHODS
  Five hundred eleven centers belonging to the Vermont Oxford Network prospectively evaluated 71,808 neonates with birth weight of 501 to 1500 g between January 2005 and December 2006. The primary outcome variable was in-hospital mortality.
  
  
  RESULTS
  Birth weight was divided into 4 categories by 250-g increments. The NEC risk (P < .001) and mortality (P < .001) decreased with higher birth weight category. Necrotizing enterocolitis was associated with a significant odds ratio for death for each category (P < .001). Across groups, the odds ratio for NEC mortality increased with higher birth weight category (category 1 = 1.6 vs category 4 = 9.9; P < .001).
  
  
  CONCLUSIONS
  The in-hospital mortality rate of neonates with NEC remains high and is significantly related to birth weight category. Although the risk and absolute mortality of NEC decrease with higher birth weight, the odds ratios indicate that NEC has a relatively greater impact upon mortality at higher birth weight. These data afford birth weight-based mortality benchmarks that may be useful in assessing single center NEC outcomes and facilitating comparisons between centers.
authors.affiliation: Department of Surgery, Children's Hospital Boston, Boston, MA 02115, USA.
authors.forename: Shimae Cross
authors.initials: SC
authors.lastname: Fitzgibbons
authors.forename: Yiming
authors.initials: Y
authors.lastname: Ching
authors.forename: David
authors.initials: D
authors.lastname: Yu
authors.forename: Joe
authors.initials: J
authors.lastname: Carpenter
authors.forename: Michael
authors.initials: M
authors.lastname: Kenny
authors.forename: Christopher
authors.initials: C
authors.lastname: Weldon
authors.forename: Craig
authors.initials: C
authors.lastname: Lillehei
authors.forename: Clarissa
authors.initials: C
authors.lastname: Valim
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Horbar
authors.forename: Tom
authors.initials: T
authors.lastname: Jaksic
mesh_terms: D019985:Benchmarking; D001724:Birth Weight; D020345:Enterocolitis, Necrotizing / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D011247:Pregnancy