Global Incidence of Necrotizing Enterocolitis: a Systematic Review and Meta-Analysis

Abstract

Abstract Background: Necrotizing Enterocolitis (NEC) is a major cause of morbidity and mortality in the Neonatal Intensive Care Unit (NICU), yet the global incidence of NEC has not been systematically evaluated. We conducted a systematic review and meta-analysis of cohort studies reporting the incidence of NEC in infants with Very Low Birth Weight (VLBW).Methods: The databases searched included PubMed, MEDLINE, the Cochrane Library, EMBASE and grey literature. Eligible studies were cohort or population-based studies of newborns including registry data reporting incidence of NEC. Data were extracted from the selected papers included incidence of NEC cases and size of population at risk, author and publication details, follow up period covered by the study, location and setting of the study and whether it was VLBW infants or preterm infants. Additionally, risk of bias assessment of the included studies were carried out using a validated tool. Bias adjusted Quality Effect Model (QEM) were used to pool the estimates. In the presence of substantial heterogeneity, Random Effect Models (REM) were used as an additionally sensitivity analyses. The heterogeneity between studies were evaluated using the Cochrane Q statistics and Higgin’s I2 value. Subgroup analysis and meta-regression were used to explore the sources of heterogeneity. Funnel plots as appropriate for ratio measures were used to assess publication bias. Results: A systematic and comprehensive search of databases identified 27 cohort studies reporting the incidence of NEC. The pooled estimate of the global incidence of NEC was 6.0% (95% CI: 4.0%-9.0%). There were substantial heterogeneity (I2 = 100%) between studies. Funnel plots showed no evidence of publication bias.Conclusion: Seven out of 100 of all VLBW infants in NICU are likely to develop NEC. However, there were considerable heterogeneity between studies. High quality studies assessing incidence of NEC along with associated risk factors are warranted.