title: Bioelectrical impedance analysis to estimate body composition in children and adolescents: a systematic review and evidence appraisal of validity, responsiveness, reliability and measurement error.
abstract: Bioelectrical impedance analysis (BIA) is a practical method to estimate percentage body fat (%BF). In this systematic review, we aimed to assess validity, responsiveness, reliability and measurement error of BIA methods in estimating %BF in children and adolescents.We searched for relevant studies in Pubmed, Embase and Cochrane through November 2012. Two reviewers independently screened titles and abstracts for inclusion, extracted data and rated methodological quality of the included studies. We performed a best evidence synthesis to synthesize the results, thereby excluding studies of poor quality. We included 50 published studies. Mean differences between BIA and reference methods (gold standard [criterion validity] and convergent measures of body composition [convergent validity]) were considerable and ranged from negative to positive values, resulting in conflicting evidence for criterion validity. We found strong evidence for a good reliability, i.e. (intra-class) correlations ≥0.82. However, test-retest mean differences ranged from 7.5% to 13.4% of total %BF in the included study samples, indicating considerable measurement error. Our systematic review suggests that BIA is a practical method to estimate %BF in children and adolescents. However, validity and measurement error are not satisfactory.
authors.affiliation: Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Talma
authors.forename: M J M
authors.initials: MJ
authors.lastname: Chinapaw
authors.forename: B
authors.initials: B
authors.lastname: Bakker
authors.forename: R A
authors.initials: RA
authors.lastname: HiraSing
authors.forename: C B
authors.initials: CB
authors.lastname: Terwee
authors.forename: T M
authors.initials: TM
authors.lastname: Altenburg
mesh_terms: D000293:Adolescent; D001823:Body Composition; D002648:Child; D017097:Electric Impedance; D006801:Humans; D015203:Reproducibility of Results
keywords: BIA; criterion validity; measurement properties; youth.