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Accuracy of self-reported body weight, height and waist circumference in a Dutch overweight working population.

Dekkers JC, van Wier MF, Hendriksen IJ, Twisk JW, van Mechelen W - BMC Med Res Methodol (2008)

Bottom Line: WC was significantly (p < 0.001) over-reported by 1.1 cm.Due to the large power of our study, the clinical significance of our statistical significant findings may be limited.ISRCTN04265725.

View Article: PubMed Central - HTML - PubMed

Affiliation: EMGO Institute and Department of Public and Occupational Health, VU University medical center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands. c.dekkers@vumc.nl

ABSTRACT

Background: In population studies, body mass index (BMI) is generally calculated from self-reported body weight and height. The self-report of these anthropometrics is known to be biased, resulting in a misclassification of BMI status. The aim of our study is to evaluate the accuracy of self-reported weight, height and waist circumference among a Dutch overweight (Body Mass Index [BMI] > or = 25 kg/m2) working population, and to determine to what extent the accuracy was moderated by sex, age, BMI, socio-economic status (SES) and health-related factors.

Methods: Both measured and self-reported body weight and body height were collected in 1298 healthy overweight employees (66.6% male; mean age 43.9 +/- 8.6 years; mean BMI 29.5 +/- 3.4 kg/m2), taking part in the ALIFE@Work project. Measured and self-reported waist circumferences (WC) were available for a sub-group of 250 overweight subjects (70.4% male; mean age 44.1 +/- 9.2 years; mean BMI 29.6 +/- 3.0 kg/m2). Intra Class Correlation (ICC), Cohen's kappa and Bland Altman plots were used for reliability analyses, while linear regression analyses were performed to assess the factors that were (independently) associated with the reliability.

Results: Body weight was significantly (p < 0.001) under-reported on average by 1.4 kg and height significantly (p < 0.001) over-reported by 0.7 cm. Consequently, BMI was significantly (p < 0.001) under-reported by 0.7 kg/m2. WC was significantly (p < 0.001) over-reported by 1.1 cm. Although the self-reporting of anthropometrics was biased, ICC's showed high concordance between measured and self-reported values. Also, substantial agreement existed between the prevalences of BMI status and increased WC based on measured and self-reported data. The under-reporting of BMI and body weight was significantly (p < 0.05) affected by measured weight, height, SES and smoking status, and the over-reporting of WC by age, sex and measured WC.

Conclusion: Results suggest that self-reported BMI and WC are satisfactorily accurate for the assessment of the prevalence of overweight/obesity and increased WC in a middle-aged overweight working population. As the accuracy of self-reported anthropometrics is affected by measured weight, height, WC, smoking status and/or SES, results for these subgroups should be interpreted with caution. Due to the large power of our study, the clinical significance of our statistical significant findings may be limited.

Trial registration: ISRCTN04265725.

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Related in: MedlinePlus

a-d. Bland-Altman plots of the difference between measured and self-reported body weight (a), height (b), BMI (c) and WC (d) plotted against the mean. In each figure, the solid line represents the mean difference between the measured and self-reported value (body weight: 1.4 kg; height: -0.7 cm; BMI: 0.7 kg/m2; WC: -1.1 cm) and the dashed lines represent the 95% limits of agreement (body weight -2.4, 5.2; body height -3.7, 2.3; BMI -0.9, 2.3; WC -8.9, 6.8).
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Figure 1: a-d. Bland-Altman plots of the difference between measured and self-reported body weight (a), height (b), BMI (c) and WC (d) plotted against the mean. In each figure, the solid line represents the mean difference between the measured and self-reported value (body weight: 1.4 kg; height: -0.7 cm; BMI: 0.7 kg/m2; WC: -1.1 cm) and the dashed lines represent the 95% limits of agreement (body weight -2.4, 5.2; body height -3.7, 2.3; BMI -0.9, 2.3; WC -8.9, 6.8).

Mentions: Figure 1a–d shows the extent of misreporting of body weight, height, BMI and WC. It can be observed that there were individual differences in the accuracy of self-reported anthropometrics. For example, the difference between measured and self-reported values of WC ranged from -8.9 cm (over-reporting) to 6.8 cm (under-reporting).


Accuracy of self-reported body weight, height and waist circumference in a Dutch overweight working population.

Dekkers JC, van Wier MF, Hendriksen IJ, Twisk JW, van Mechelen W - BMC Med Res Methodol (2008)

a-d. Bland-Altman plots of the difference between measured and self-reported body weight (a), height (b), BMI (c) and WC (d) plotted against the mean. In each figure, the solid line represents the mean difference between the measured and self-reported value (body weight: 1.4 kg; height: -0.7 cm; BMI: 0.7 kg/m2; WC: -1.1 cm) and the dashed lines represent the 95% limits of agreement (body weight -2.4, 5.2; body height -3.7, 2.3; BMI -0.9, 2.3; WC -8.9, 6.8).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2605752&req=5

Figure 1: a-d. Bland-Altman plots of the difference between measured and self-reported body weight (a), height (b), BMI (c) and WC (d) plotted against the mean. In each figure, the solid line represents the mean difference between the measured and self-reported value (body weight: 1.4 kg; height: -0.7 cm; BMI: 0.7 kg/m2; WC: -1.1 cm) and the dashed lines represent the 95% limits of agreement (body weight -2.4, 5.2; body height -3.7, 2.3; BMI -0.9, 2.3; WC -8.9, 6.8).
Mentions: Figure 1a–d shows the extent of misreporting of body weight, height, BMI and WC. It can be observed that there were individual differences in the accuracy of self-reported anthropometrics. For example, the difference between measured and self-reported values of WC ranged from -8.9 cm (over-reporting) to 6.8 cm (under-reporting).

Bottom Line: WC was significantly (p < 0.001) over-reported by 1.1 cm.Due to the large power of our study, the clinical significance of our statistical significant findings may be limited.ISRCTN04265725.

View Article: PubMed Central - HTML - PubMed

Affiliation: EMGO Institute and Department of Public and Occupational Health, VU University medical center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands. c.dekkers@vumc.nl

ABSTRACT

Background: In population studies, body mass index (BMI) is generally calculated from self-reported body weight and height. The self-report of these anthropometrics is known to be biased, resulting in a misclassification of BMI status. The aim of our study is to evaluate the accuracy of self-reported weight, height and waist circumference among a Dutch overweight (Body Mass Index [BMI] > or = 25 kg/m2) working population, and to determine to what extent the accuracy was moderated by sex, age, BMI, socio-economic status (SES) and health-related factors.

Methods: Both measured and self-reported body weight and body height were collected in 1298 healthy overweight employees (66.6% male; mean age 43.9 +/- 8.6 years; mean BMI 29.5 +/- 3.4 kg/m2), taking part in the ALIFE@Work project. Measured and self-reported waist circumferences (WC) were available for a sub-group of 250 overweight subjects (70.4% male; mean age 44.1 +/- 9.2 years; mean BMI 29.6 +/- 3.0 kg/m2). Intra Class Correlation (ICC), Cohen's kappa and Bland Altman plots were used for reliability analyses, while linear regression analyses were performed to assess the factors that were (independently) associated with the reliability.

Results: Body weight was significantly (p < 0.001) under-reported on average by 1.4 kg and height significantly (p < 0.001) over-reported by 0.7 cm. Consequently, BMI was significantly (p < 0.001) under-reported by 0.7 kg/m2. WC was significantly (p < 0.001) over-reported by 1.1 cm. Although the self-reporting of anthropometrics was biased, ICC's showed high concordance between measured and self-reported values. Also, substantial agreement existed between the prevalences of BMI status and increased WC based on measured and self-reported data. The under-reporting of BMI and body weight was significantly (p < 0.05) affected by measured weight, height, SES and smoking status, and the over-reporting of WC by age, sex and measured WC.

Conclusion: Results suggest that self-reported BMI and WC are satisfactorily accurate for the assessment of the prevalence of overweight/obesity and increased WC in a middle-aged overweight working population. As the accuracy of self-reported anthropometrics is affected by measured weight, height, WC, smoking status and/or SES, results for these subgroups should be interpreted with caution. Due to the large power of our study, the clinical significance of our statistical significant findings may be limited.

Trial registration: ISRCTN04265725.

Show MeSH
Related in: MedlinePlus