Is phase angle an appropriate indicator of malnutrition in different disease states? A systematic review

Background & aims: Subjective Global Assessment (SGA) classifies malnutrition severity via a simple bedside assessment. Phase angle (PhA) is an indicator of cell integrity and has been suggested to be indicator of nutritional status. Objective: To explore the relationship between PhA and SGA. Methods: Relevant studies published through October 31, 2017 were identified using 7 electronic databases. Articles were included for review if they included comparison data between SGA and PhA within adult disease populations. Evidence quality was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) guidelines and methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Results: 33 articles within four disease states (liver, hospitalization, oncology and renal) met inclusion criteria for review. Results were limited by restricting the database search to articles published in English only, and by the inherent difficulty of comparing 2 methods which are both influenced by the operator. Conclusion: Based on GRADE guidelines, evidence quality received a grade of Low. Based on QUADAS-2, 61% of studies had high risk of bias in the index test (PhA), while all other domains had low risk. It is not possible to conclude that PhA is an accurate independent indicator of malnutrition. (C) 2018 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.