Incidence and risk of necrotizing enterocolitis in Denmark from 1994-2014

We suspected that the incidence of NEC in Denmark had increased during the last 20 years but hypothesized that this could be explained by the increased neonatal survival. We conducted a retrospective, observational cohort study of all registered liveborn infants in Denmark in the period from January 1, 1994 to December 31, 2014. Data were obtained from the Medical Birth Registry, National Patient Register, and Cause of Death register in Denmark. The primary outcome was the registration of NEC (ICD-10: DP77.9) during a hospital admission within 6 months after birth. The statistical analysis used 'death before NEC' as a competing risk. The cohort consisted of 1,351,675 infants, of which 8,059 died. There was a strongly significant decreasing risk of death over the period for the all infants (p