Variations in incidence of necrotizing enterocolitis in Canadian neonatal intensive care units

Necrotizing enterocolitis (NEC) is the most common acquired intestinal disease of neonates. Previous reports on incidence have generally examined small cohorts of extremely low-birth-weight infants and have not examined risk-adjusted variations among neonatal intensive care units (NICUs). The authors examined risk-adjusted variations in the incidence of NEC in a large group of Canadian NICUs and explored possible therapy-related risks.

The authors obtained data on 18,234 infants admitted to 17 tertiary level Canadian NICUs from January 1996 to October 1997. They used multivariate logistic regression analysis to examine the inter-NICU variation in incidence of NEC, with adjustment for population risk factors and admission illness severity, and explored therapy-related variables.

The incidence of NEC was 6.6% (n = 238) among 3,628 infants with birth weight < or = 1,500 g (VLBW), and 0.7% (n = 98) among 14,606 infants with birth weight > 1,500 g (HBW). Multivariate logistic regression analysis showed that for VLBW infants, NEC was associated with lower gestational age and treatment for hypotension and patent ductus arteriosus. Among HBW infants, NEC was associated with lower gestational age, presence of congenital anomalies (cardiovascular, digestive, musculoskeletal, multiple systems) and need for assisted ventilation. There was no significant variation in the risk-adjusted incidence of NEC among NICUs, with the exception of one NICU reporting no cases of NEC.

Risk factors for NEC were different in VLBW and HBW infants. There was no significant variation in the risk-adjusted incidence of NEC among Canadian NICUs, with one possible exception.