Diagnostic performance of body mass index to identify obesity as defined by body adiposity in children and adolescents: a systematic review and meta‐analysis

Abstract

Summary: Background: The ideal means of identifying obesity in children and adolescents has not been determined although body mass index (BMI) is the most widely used screening tool. Objective: We performed a systematic review and meta‐analysis of studies assessing the diagnostic performance of BMI to detect adiposity in children up to 18 years. Methods: Data sources were EMBASE, MEDLINE, C ochrane, D atabase of S ystematic R eviews C ochrane CENTRAL, W eb of S cience and SCOPUS up to M arch 2013. Studies providing measures of diagnostic performance of BMI and using body composition technique for body fat percentage measurement were included. Results: Thirty‐seven eligible studies that evaluated 53 521 patients, with mean age ranging from 4 to 18 years were included in the meta‐analysis. Commonly used BMI cut‐offs for obesity showed pooled sensitivity to detect high adiposity of 0.73 (confidence interval [CI] 0.67–0.79), specificity of 0.93 (CI 0.88–0.96) and diagnostic odds ratio of 36.93 (CI 20.75–65.71). Males had lower sensitivity. Moderate heterogeneity was observed (I2 = 48%) explained in meta‐regression by differences across studies in race, BMI cut‐off, BMI reference criteria (C enter for D isease C ontrol vs. I nternational O besity T ask F orce) and reference standard method assessing adiposity. Conclusion: BMI has high specificity but low sensitivity to detect excess adiposity and fails to identify over a quarter of children with excess body fat percentage.