Objective Lack of a universal case-definition hinders (NEC) surveillance and clinical trials. Bell’s staging, although widely used, was devised to guide surgical management after diagnosis1. We aimed to develop an evidence-based NEC case-definition.
Methods We used the National Neonatal Research Database, that holds data extracted from the electronic records of babies admitted to NHS neonatal units, to obtain variables for infants receiving a laparotomy between November 2011–May 2013 (gestation, clinical signs (abdominal distension, tenderness, discolouration, mass, increased and/or bilious aspirates, bloody and/or mucousy stools), radiological signs (pneumatosis, air in the liver, pneumoperitoneum, fixed loop, gasless), confirmed NEC (at surgery or post-mortem). We developed case-definitions using logistic regression and classification trees2, and calculated sensitivity, specificity and area under the receiver operating characteristic curve (AUC). Interim validation was conducted using a separate dataset covering June–December 2013.
Results We identified 142 infants from 40 neonatal units; 60 had confirmed NEC. The logistic regression definition comprised “pneumatosis OR two or more of (a) abdominal discolouration, (b) gasless X-ray (c) pneumoperitoneum” (sensitivity 0.72, specificity 0.88, AUC 0.8) and classification tree definition “pneumatosis OR abdominal discolouration OR [pneumoperitoneum AND aspirates]” (sensitivity 0.85, specificity 0.78, AUC 0.82). Validation showed logistic regression: sensitivity 0.64, specificity 0.95, AUC 0.85; classification tree sensitivity 0.67, specificity 0.91, AUC 0.79.
Conclusion Our interim analysis shows that the two methods derived similar definitions identifying a similar proportion of cases; pneumatosis was the strongest predictor. The final analysis will include data from June 2013-April 2014 and will investigate gestation-specific effects.
Bell MJ, Ternberg JL, Feigin RD , et al. Neonatal necrotizing enterocolitis. Therapeutic decisions based upon clinical staging. Ann Surg. 1978;187:1–7 Online First: 1978/01/01]
Crichton NJ, Hinde JP, Marchini J. Models for diagnosing chest pain: is CART helpful? Stat Med. 1997;16:717–27 Online
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.