Accuracy of self-reported body weight: Stepped Approach Model component assessment

Abstract

This study was conducted to investigate innovative solutions to a measurement problem pertaining to self-reported body weight data as a key component of the Stepped Approach Model (SAM) of service delivery. Subjects (n = 223) were randomly assigned to one of two conditions: Informed Group (of self-report and weight measurement) + six body weighing habit items (IG, n = 113) and Uninformed Group (of self-report and weight measurement) + one body weight item (UG, n = 110). A t-test indicated that IG subjects reported significantly more accurately, t(194) = 2.99, P = 0.002, and with significantly less variability than UG subjects, F(109,112) = 1.95, P < 0.0005. A multiple regression of absolute difference weight (observed--self-reported weight) on observed weight revealed consistent accuracy across the weight range for IG subjects, whereas UG subjects' accuracy decreased as body weight increased. The slope of the IG did not significantly differ from 0, t(218) = 1.44, P = 0.150, but did significantly differ from the slope of the UG, t(218) = 2.78, P = 0.006. The following conclusions are noted when IG conditions are used: (1) a three-component strategy designed for maximum effect size results in accurate reporting across the entire weight range, (2) self-reported body weights under prescribed conditions can be used as valid 'proxies' for observed measurements, and (3) SAM proponents can rely on the validity of self-report body weight as a credible basis for decisions about changing intervention steps and evaluating intervention efficacy.

Trends in National and State-Level Obesity in the USA after Correction for Self-Report Bias: Analysis of Health Surveys

“…Previous reports on bias in self-reported weight and height [9][10][11][12][13][14] had all been based on individual-level data. As a result, these works could not examine two factors important for population-level monitoring: first, individuallevel misreporting caused by absence of measurement subsequent/previous to the interview and by the mode of self-report, and second, differential participation based on the survey mode.…”

“…Self-reported weight and height data are subject to random error, and, more importantly, systematic reporting bias. [9][10][11][12][13][14] The magnitude of bias has varied across studies based on factors such as age, actual weight and height, and education. 9 Some researchers have nonetheless concluded that self-reported height and weight are acceptable, valid, or excellent for population-based studies.…”

Grandparental and Parental Obesity Influences on Childhood Overweight: Implications for Primary Care Practice

“…Estimates of the prevalence of obesity based on self-report may be affected by bias toward lower BMI from underreporting of weight influenced by social desirability. 19,20 Of note, self-report adult BMI data from the PSID closely match other self-report data available from concurrent waves of the National Health Interview Survey. 21 Another limitation is that we assessed intrafamilial BMI associations at one point in time; future work will permit assessments of these relationships over longer periods.…”

The Supplemental Nutrition Assistance Program, energy balance, and weight gain

“…The underreporting bias may be mitigated in the present case because survey respondents answered the question about past weight after having been weighed. Black et al (1998) found that the accuracy of self-reported weight did not decrease as weight increased for individuals who knew they would have their weight measured following the weight survey. Moreover, as long as SNAP participants are not more or less likely than nonparticipants to underreport past weight, we can still consistently estimate the difference in weight gain between the two groups.…”