The presence and effect of bias in trials of early enteral nutrition in critical care.

Abstract

BACKGROUND:

Randomized trials suggest that early enteral nutrition is beneficial in critically ill adults. However, methodologic bias can overestimate benefit.

OBJECTIVE:

To assess the potential effect of methodologic bias on these trials.

STUDY DESIGN:

Systematic review and meta-analysis.

DATA SOURCE:

Randomized trials identified in electronic searches of PUBMED, EMBASE, and the Cochrane Library, and in various handsearches.

METHODS:

The primary (mortality, morbidity) and secondary (time on ventilator or in intensive care unit/hospital, cost) outcomes were abstracted from each identified trial comparing early enteral nutrition to no/delayed enteral nutrition. Each trial was assessed for six domains of methodologic bias (sequence generation, allocation concealment, blinding, intention-to-treat, selective outcome reporting, other). No low risk of bias trial (adequate in all six domains) was identified, so such trials could not be compared to the others. Instead, meta-analyses of trials with more or fewer risks were compared in the following ways: adequate methodology to deal with ≥3 or ≤2 domains; Jadad scores ≥3 or ≤2; adequate versus not adequate for each domain.

DATA SYNTHESIS:

In the 15 identified trials, early enteral nutrition appeared to improve mortality and infectious morbidity. Mortality benefit was observed only in trials with more risks of bias; infectious morbidity benefit was observed in some analyses of trials with fewer bias risks.

LIMITATIONS:

Small numbers of trials and missing information.

CONCLUSIONS:

The benefits attributed to early enteral nutrition were either seen only in trials with high risks of bias or may result from residual risks of bias.

• Authors: Ronald L Koretz, Timothy O Lipman
• Journal: Clinical nutrition (Edinburgh, Scotland) (Clin Nutr) Vol. 33 Issue 2 Pg. 240-5 (Apr 2014) ISSN: 1532-1983 [Electronic] England
• PMID: 23845382 (Publication Type: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't, Review, Systematic Review)
• Copyright: Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Topics

• Bias
• Critical Care (methods)
• Critical Illness (therapy)
• Enteral Nutrition (methods)
• Humans
• Intensive Care Units
• Randomized Controlled Trials as Topic
• Research Design
• Treatment Outcome