Sensitivity and specificity of body mass index in determining obesity in children

Background: The purpose of this study is to determine sensitivity and specificity of body mass index (BMI) based on Center for Disease Control 2000 (CDC) percentiles compared to fat mass index (FMI) as an indicator of being really obese in children. Obesity was compared based on these two indexes am...

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Main Authors: Mehnoosh Samadi, Haleh Sadrzade- Yeganeh, Leila Azadbakht, Kourosh Jafarian, Abbas Rahimi, Gity Sotoudeh
Format: Article
Language:English
Published: Wolters Kluwer Medknow Publications 2013-01-01
Series:Journal of Research in Medical Sciences
Subjects:
Online Access:http://www.jmsjournal.net/article.asp?issn=1735-1995;year=2013;volume=18;issue=7;spage=537;epage=542;aulast=Samadi
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author Mehnoosh Samadi
Haleh Sadrzade- Yeganeh
Leila Azadbakht
Kourosh Jafarian
Abbas Rahimi
Gity Sotoudeh
author_facet Mehnoosh Samadi
Haleh Sadrzade- Yeganeh
Leila Azadbakht
Kourosh Jafarian
Abbas Rahimi
Gity Sotoudeh
author_sort Mehnoosh Samadi
collection DOAJ
description Background: The purpose of this study is to determine sensitivity and specificity of body mass index (BMI) based on Center for Disease Control 2000 (CDC) percentiles compared to fat mass index (FMI) as an indicator of being really obese in children. Obesity was compared based on these two indexes among children under study. Materials and Methods: This cross-sectional study was conducted on 410 primary school girls aged 8-10 years, in the city of Esfahan. Weight and height were measured and BMI was calculated based on weight divided by height squared. Fat mass was measured by body composition analyzer (BCA) and FMI was calculated by dividing fat mass by height squared. FMI at or above the 90 th percentile and FMI less than 90 th percentile of reference data were considered as criterion for defining real obesity and normal adiposity, respectively. Receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of FMI. Furthermore, the rate of agreement between two indices was calculated using Kappa coefficient P number. Results: Mean and standard deviation of FMI and BMI in all children were 6 ± 2.1 (kg/m 2 ) and 19.4 ± 3 (kg/m 2 ), respectively. The area under the ROC curve for obesity was 0.75. The cutoff point, sensitivity, and specificity of BMI to classify children as obese compared to FMI were 21.2 kg/m 2 , 79%, and 73%, respectively. In this cutoff point for BMI (21.2 kg/m 2 ), the agreement rate between BMI and FMI for determining obesity status was 0.5 (P < 0.001). Conclusion: Our results indicated 79% of children who were recognized as obese based on FMI, were also classified as obese according to BMI. Twenty-seven percent of children, who were non-obese, were identified as obese based on BMI. It appears that FMI compared to BMI is more accurate in determining obesity, but further studies are required.
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spelling doaj.art-72a54577f2fb4838ae22444e4f60230b2022-12-21T18:49:36ZengWolters Kluwer Medknow PublicationsJournal of Research in Medical Sciences1735-19951735-71362013-01-01187537542Sensitivity and specificity of body mass index in determining obesity in childrenMehnoosh SamadiHaleh Sadrzade- YeganehLeila AzadbakhtKourosh JafarianAbbas RahimiGity SotoudehBackground: The purpose of this study is to determine sensitivity and specificity of body mass index (BMI) based on Center for Disease Control 2000 (CDC) percentiles compared to fat mass index (FMI) as an indicator of being really obese in children. Obesity was compared based on these two indexes among children under study. Materials and Methods: This cross-sectional study was conducted on 410 primary school girls aged 8-10 years, in the city of Esfahan. Weight and height were measured and BMI was calculated based on weight divided by height squared. Fat mass was measured by body composition analyzer (BCA) and FMI was calculated by dividing fat mass by height squared. FMI at or above the 90 th percentile and FMI less than 90 th percentile of reference data were considered as criterion for defining real obesity and normal adiposity, respectively. Receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of FMI. Furthermore, the rate of agreement between two indices was calculated using Kappa coefficient P number. Results: Mean and standard deviation of FMI and BMI in all children were 6 ± 2.1 (kg/m 2 ) and 19.4 ± 3 (kg/m 2 ), respectively. The area under the ROC curve for obesity was 0.75. The cutoff point, sensitivity, and specificity of BMI to classify children as obese compared to FMI were 21.2 kg/m 2 , 79%, and 73%, respectively. In this cutoff point for BMI (21.2 kg/m 2 ), the agreement rate between BMI and FMI for determining obesity status was 0.5 (P < 0.001). Conclusion: Our results indicated 79% of children who were recognized as obese based on FMI, were also classified as obese according to BMI. Twenty-seven percent of children, who were non-obese, were identified as obese based on BMI. It appears that FMI compared to BMI is more accurate in determining obesity, but further studies are required.http://www.jmsjournal.net/article.asp?issn=1735-1995;year=2013;volume=18;issue=7;spage=537;epage=542;aulast=SamadiBody mass indexchildrenfat mass indexobesity
spellingShingle Mehnoosh Samadi
Haleh Sadrzade- Yeganeh
Leila Azadbakht
Kourosh Jafarian
Abbas Rahimi
Gity Sotoudeh
Sensitivity and specificity of body mass index in determining obesity in children
Journal of Research in Medical Sciences
Body mass index
children
fat mass index
obesity
title Sensitivity and specificity of body mass index in determining obesity in children
title_full Sensitivity and specificity of body mass index in determining obesity in children
title_fullStr Sensitivity and specificity of body mass index in determining obesity in children
title_full_unstemmed Sensitivity and specificity of body mass index in determining obesity in children
title_short Sensitivity and specificity of body mass index in determining obesity in children
title_sort sensitivity and specificity of body mass index in determining obesity in children
topic Body mass index
children
fat mass index
obesity
url http://www.jmsjournal.net/article.asp?issn=1735-1995;year=2013;volume=18;issue=7;spage=537;epage=542;aulast=Samadi
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AT leilaazadbakht sensitivityandspecificityofbodymassindexindeterminingobesityinchildren
AT kouroshjafarian sensitivityandspecificityofbodymassindexindeterminingobesityinchildren
AT abbasrahimi sensitivityandspecificityofbodymassindexindeterminingobesityinchildren
AT gitysotoudeh sensitivityandspecificityofbodymassindexindeterminingobesityinchildren