F Shiely1,2, H Y Ng3, E M Berkery4, C Murrin5, C Kelleher5, K Hayes4. 1. Department of Epidemiology and Public Health, University College Cork, Cork, Ireland. 2. HRB Clinical Research Facility, Mercy University Hospital, Grenville Place, Cork, Ireland. 3. School of Medicine, University College Cork, Brookfield Health Sciences Complex, Cork, Ireland. 4. Department of Mathematics and Statistics, University of Limerick, Plassey, Limerick, Ireland. 5. School of Public Health, Physiotherapy and Sports Science, University College Dublin, Belfield, Dublin 4, Ireland.
Abstract
BACKGROUND: The gold standard for categorisation of weight status is clinically measured body mass index (BMI), but this is often not practical in large epidemiological studies. OBJECTIVES: To determine if a child's weight perception or a mother's perception of a child's weight status is a viable alternative to measured height and weight in determining BMI classification. Secondary outcomes are to determine the influence of a mother's BMI on her ability to categorise the child's BMI and a child's ability to recognise his/her own BMI. METHODS: Cross-sectional analysis of the growing up in Ireland cohort study, a nationally representative cohort of 8568 9-year-old children. The variables considered for this analysis are the child's gender, BMI (International Obesity Taskforce grade derived from measured height and weight) and self-perceived weight status, and the mother's weight perception of the child, BMI (derived from measured height and weight) and self-perceived weight status. Cohen's weighted-kappa was used to evaluate the strength of the agreement between pairwise combinations of the BMI variables. Cumulative and adjacent categories logistic regression were used to predict how likely a person rates themselves as under, normal or overweight, based on explanatory variables. RESULTS: Mothers are more accurate at correctly classifying their child's BMI (κ=0.5; confidence intervals (CI) 0.38-0.51) than the children themselves (κ=0.25; CI 0.23-0.26). Overweight mothers are better raters of their child's BMI (κ=0.51; CI 0.49-0.54), compared with normal (κ=0.44; CI 0.41-0.47) or underweight mothers (κ=0.4; CI 0.22-0.58), regardless of whether the mother's BMI is derived from measured height and weight or self-perceived. The mother's perception of the child's weight status is not an influencing factor on the child's ability to correctly classify him/herself, but the child's self-perceived weight status influences the mother's ability to correctly classify the child. CONCLUSIONS: A mother's BMI classification of her child is a viable alternative to BMI measurement in large epidemiological studies.
BACKGROUND: The gold standard for categorisation of weight status is clinically measured body mass index (BMI), but this is often not practical in large epidemiological studies. OBJECTIVES: To determine if a child's weight perception or a mother's perception of a child's weight status is a viable alternative to measured height and weight in determining BMI classification. Secondary outcomes are to determine the influence of a mother's BMI on her ability to categorise the child's BMI and a child's ability to recognise his/her own BMI. METHODS: Cross-sectional analysis of the growing up in Ireland cohort study, a nationally representative cohort of 8568 9-year-old children. The variables considered for this analysis are the child's gender, BMI (International Obesity Taskforce grade derived from measured height and weight) and self-perceived weight status, and the mother's weight perception of the child, BMI (derived from measured height and weight) and self-perceived weight status. Cohen's weighted-kappa was used to evaluate the strength of the agreement between pairwise combinations of the BMI variables. Cumulative and adjacent categories logistic regression were used to predict how likely a person rates themselves as under, normal or overweight, based on explanatory variables. RESULTS: Mothers are more accurate at correctly classifying their child's BMI (κ=0.5; confidence intervals (CI) 0.38-0.51) than the children themselves (κ=0.25; CI 0.23-0.26). Overweight mothers are better raters of their child's BMI (κ=0.51; CI 0.49-0.54), compared with normal (κ=0.44; CI 0.41-0.47) or underweight mothers (κ=0.4; CI 0.22-0.58), regardless of whether the mother's BMI is derived from measured height and weight or self-perceived. The mother's perception of the child's weight status is not an influencing factor on the child's ability to correctly classify him/herself, but the child's self-perceived weight status influences the mother's ability to correctly classify the child. CONCLUSIONS: A mother's BMI classification of her child is a viable alternative to BMI measurement in large epidemiological studies.
Authors: Paul C Young; Sandra DeBry; W Daniel Jackson; Julie Metos; Elizabeth Joy; Mark Templeman; Chuck Norlin Journal: Clin Pediatr (Phila) Date: 2010-10 Impact factor: 1.168
Authors: Margaret M Weden; Peter B Brownell; Michael S Rendall; Christopher Lau; Meenakshi Fernandes; Zafar Nazarov Journal: Am J Epidemiol Date: 2013-06-19 Impact factor: 4.897
Authors: Frances Shiely; Ivan J Perry; Jennifer Lutomski; Janas Harrington; C Cecily Kelleher; Hannah McGee; Kevin Hayes Journal: BMC Public Health Date: 2010-09-17 Impact factor: 3.295