title: Mean Expected Error in Prediction of Total Body Water: A True Accuracy Comparison between Bioimpedance Spectroscopy and Single Frequency Regression Equations.
abstract: For several decades electrical bioimpedance (EBI) has been used to assess body fluid distribution and body composition. Despite the development of several different approaches for assessing total body water (TBW), it remains uncertain whether bioimpedance spectroscopic (BIS) approaches are more accurate than single frequency regression equations. The main objective of this study was to answer this question by calculating the expected accuracy of a single measurement for different EBI methods. The results of this study showed that all methods produced similarly high correlation and concordance coefficients, indicating good accuracy as a method. Even the limits of agreement produced from the Bland-Altman analysis indicated that the performance of single frequency, Sun's prediction equations, at population level was close to the performance of both BIS methods; however, when comparing the Mean Absolute Percentage Error value between the single frequency prediction equations and the BIS methods, a significant difference was obtained, indicating slightly better accuracy for the BIS methods. Despite the higher accuracy of BIS methods over 50 kHz prediction equations at both population and individual level, the magnitude of the improvement was small. Such slight improvement in accuracy of BIS methods is suggested insufficient to warrant their clinical use where the most accurate predictions of TBW are required, for example, when assessing over-fluidic status on dialysis. To reach expected errors below 4-5%, novel and individualized approaches must be developed to improve the accuracy of bioimpedance-based methods for the advent of innovative personalized health monitoring applications.
authors.affiliation: Faculty of Care Science, Work Life and Social Welfare, University of Borås, 501 90 Borås, Sweden ; School of Technology and Health, Royal Institute of Technology, 141 52 Huddinge, Sweden.
authors.forename: Fernando
authors.identifier: 0000-0002-6995-967X
authors.initials: F
authors.lastname: Seoane
authors.affiliation: Department of Oncology, Karolinska University Hospital, 171 76 Stockholm, Sweden.
authors.forename: Shirin
authors.initials: S
authors.lastname: Abtahi
authors.affiliation: School of Technology and Health, Royal Institute of Technology, 141 52 Huddinge, Sweden ; Department of Clinical Science, Intervention and Technology, Karolinska Institute, Hälsovägen 7, 141 57 Stockholm, Sweden.
authors.forename: Farhad
authors.initials: F
authors.lastname: Abtahi
authors.affiliation: Department of Clinical Nutrition, The Sahlgrenska Academy, The University of Gothenburg, Sahlgrenska University Hospital, 405 30 Göteborg, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Ellegård
authors.affiliation: Department of Clinical Nutrition, The Sahlgrenska Academy, The University of Gothenburg, Sahlgrenska University Hospital, 405 30 Göteborg, Sweden.
authors.forename: Gudmundur
authors.initials: G
authors.lastname: Johannsson
authors.affiliation: Department of Clinical Nutrition, The Sahlgrenska Academy, The University of Gothenburg, Sahlgrenska University Hospital, 405 30 Göteborg, Sweden.
authors.forename: Ingvar
authors.initials: I
authors.lastname: Bosaeus
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, AU 7072, Australia.
authors.forename: Leigh C
authors.identifier: 0000-0003-2378-279X
authors.initials: LC
authors.lastname: Ward
mesh_terms: D000368:Aged; D001823:Body Composition / Q000502:physiology*; D001826:Body Fluids / Q000502:physiology; D001834:Body Water / Q000502:physiology*; D058266:Dielectric Spectroscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D057285:Precision Medicine; D006435:Renal Dialysis