title: Parent-reported height and weight as sources of bias in survey estimates of childhood obesity.
abstract: Parental reporting of height and weight was evaluated for US children aged 2-13 years. The prevalence of obesity (defined as a body mass index value (calculated as weight (kg)/height (m)(2)) in the 95th percentile or higher) and its height and weight components were compared in child supplements of 2 nationally representative surveys: the 1996-2008 Children of the National Longitudinal Survey of Youth 1979 Cohort (NLSY79-Child) and the 1997 Child Development Supplement of the Panel Study of Income Dynamics (PSID-CDS). Sociodemographic differences in parent reporting error were analyzed. Error was largest for children aged 2-5 years. Underreporting of height, not overreporting of weight, generated a strong upward bias in obesity prevalence at those ages. Frequencies of parent-reported heights below the Centers for Disease Control and Prevention's (Atlanta, Georgia) first percentile were implausibly high at 16.5% (95% confidence interval (CI): 14.3, 19.0) in the NLSY79-Child and 20.6% (95% CI: 16.0, 26.3) in the PSID-CDS. They were highest among low-income children at 33.2% (95% CI: 22.4, 46.1) in the PSID-CDS and 26.2% (95% CI: 20.2, 33.2) in the NLSY79-Child. Bias in the reporting of obesity decreased with children's age and reversed direction at ages 12-13 years. Underreporting of weight increased with age, and underreporting of height decreased with age. We recommend caution to researchers who use parent-reported heights, especially for very young children, and offer practical solutions for survey data collection and research on child obesity.
authors.affiliation: Economics, Sociology, and Statistics, Rand Corporation, 1776 Main Street, Santa Monica, CA 90401-3208, USA. mweden@rand.org
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Weden
authors.forename: Peter B
authors.initials: PB
authors.lastname: Brownell
authors.forename: Michael S
authors.initials: MS
authors.lastname: Rendall
authors.forename: Christopher
authors.initials: C
authors.lastname: Lau
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Fernandes
authors.forename: Zafar
authors.initials: Z
authors.lastname: Nazarov
mesh_terms: D000293:Adolescent; D000328:Adult; D015982:Bias; D001827:Body Height; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D010290:Parents; D011159:Population Surveillance / Q000379:methods*; D015995:Prevalence; D012107:Research Design; D012959:Socioeconomic Factors; D014342:Truth Disclosure; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: body height; body mass index; body weights and measures; child; data reporting; demographic factors; obesity; socioeconomic factors