The age of necrotizing enterocolitis onset: an application of Sartwell's incubation period model

J Perinatol. 2011 Aug;31(8):519-23. doi: 10.1038/jp.2010.193. Epub 2011 Jan 27.


Objective: Model age of necrotizing enterocolitis (NEC) onset applying Sartwell's model of incubation periods, and examine its relationship to gestational age (GA).

Study design: Retrospective chart review of St Louis Children's Hospital neonates diagnosed with NEC (≥Bell's stage II) from 2004 to 2008, inclusive.

Result: The relationship between age of NEC (N=84 cases) onset and GA best fits a non-linear model, with infants ≤28 weeks having a disproportionately longer time to onset than older GA groups and explained 50.3% of the variability in age of NEC onset. Additional clinical variables provided no improvement in explaining age of NEC onset. Application of Sartwell's model to age of NEC onset proved a good fit, when birth is used as the common exposure episode, and age is equivalent of the incubation period.

Conclusion: The relationship between day of NEC diagnosis and GA is non-linear, with lower GA infants having disproportionately longer time to onset. Despite these GA differences, the fit to Sartwell's model for incubation periods model is consistent with NEC being a consequence of an event that occurs at or soon after birth.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age of Onset
  • Enterocolitis, Necrotizing / epidemiology*
  • Female
  • Gestational Age*
  • Humans
  • Infant, Newborn
  • Infectious Disease Incubation Period*
  • Male
  • Models, Statistical
  • Nonlinear Dynamics