Evaluation of the quality of evidence supporting guideline recommendations for the nutritional management of critically ill adults

Abstract

Aims: The primary aim of this study was to evaluate the quality of evidence supporting the 2019 European Society for Clinical Nutrition and Metabolism (ESPEN) and 2016 American Society for Parenteral and Enteral Nutrition (ASPEN) recommendations for medical nutrition therapy in critically ill patients. Secondary objectives are to assess the differences between 2019 ESPEN and 2016 ASPEN recommendations and to inform relevant stakeholders of areas requiring improvement in the research.

Methods: The 2019 ESPEN and 2016 ASPEN guidelines were identified and downloaded from the official websites. The level of evidence and strength of recommendations from the guidelines were standardised to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Level of evidence was classified as high-quality (randomised controlled trials (RCTs) without important limitations), moderate-quality (downgraded RCTs or upgraded observational studies) or low-quality (observational studies without specific strengths or important limitations, case series, case reports). In addition, good practice points (GPP; recommendations based on the clinical experience of the guideline development group) were considered. Strength of recommendation was reported as strong or weak.

Results: From 152 total recommendations, only five (3.3%) were supported by high-quality evidence, with 14 being strong recommendations. A total of 79 (52.0%) recommendations were GPPs. Overall, the proportion of recommendations supported by high-quality (7% [ESPEN] vs. 1.1% [ASPEN], p < 0.05) and moderate-quality evidence (33.3% [ESPEN] vs. 8.4% [ASPEN], p < 0.01) was significantly higher in ESPEN guidelines. On the other hand, ASPEN guidelines reported a greater proportion of recommendations supported by GPPs (58.9% [ASPEN] vs. 40.4% [ESPEN], p = 0.03). In enteral and parenteral nutrition, the proportion of recommendations supported by moderate-quality evidence (50% [ESPEN] vs. 15.8% [ASPEN], p < 0.01) was significantly higher in ESPEN guidelines.

Conclusion: Published guideline recommendations for the nutritional management of critically ill adults remain largely supported by expert opinion and only a minority by high-quality evidence. An urgent unmet clinical need for high-quality clinical trials is warranted.

Keywords: Clinical practice guidelines; Enteral nutrition; GRADE; Intensive care unit; Parenteral nutrition; Quality of evidence.