Accuracy and reliability of self-reported weight and height in the Sister Study

Abstract

Objective To assess accuracy and reliability of self-reported weight and height and identify factors associated with reporting accuracy. Design Analysis of self-reported and measured weight and height from participants in the Sister Study (2003–2009), a nationwide cohort of 50,884 women aged 35–74 in the United States with a sister with breast cancer. Setting Weight and height were reported via computer-assisted telephone interview (CATI) and self-administered questionnaires, and measured by examiners. Subjects Early enrollees in the Sister Study. There were 18,639 women available for the accuracy analyses and 13,316 for the reliability analyses. Results Using weighted kappa statistics, comparisons were made between CATI responses and examiner measures to assess accuracy and CATI and questionnaire responses to assess reliability. Polytomous logistic regression evaluated factors associated with over- or under-reporting. Compared to measured values, agreement was 96% for reported height (±1 inch; weighted kappa 0.84) and 67% for weight (±3 pounds; weighted kappa 0.92). Obese women [body mass index (BMI) ≥30 kg/m2)] were more likely than normal weight women to under-report weight by ≥5% and underweight women (BMI <18.5 kg/m2) were more likely to over-report. Among normal and overweight women (18.5 kgm2≤ BMI <30 kgm2), weight cycling and lifetime weight difference ≥50 pounds were associated with over-reporting. Conclusions U.S. women in the Sister Study were reasonably reliable and accurate in reporting weight and height. Women with normal-range BMI reported most accurately. Overweight and obese women and those with weight fluctuations were less accurate, but even among obese women, few under-reported their weight by >10%.

The impact of nutritional labels and socioeconomic status on energy intake. An experimental field study

“…18 Post hoc tests indicated that seeing either label was associated with significantly reduced 19 consumption as overweight increased and with significantly reduced consumption in weight- 20 concerned participants of lowest SES. 21 These results provide some support for previous research finding paradoxical effects of 22 nutritional labelling. However, taking account of the behaviour of non weight concerned 23 eaters and those seeing different labels, it is apparent that this effect in those of higher SES 24 is a consequence of reduced consumption in non weight concerned eaters seeing a low fat 25 label rather than increased consumption in weight concerned eaters seeing the low fat label.…”

“…Specifically, the data in Figure 1 suggested that, although there 20 was no moderating effect of BMI on the relationship between label and consumption, obese 21 participants seemed to eat less in response to seeing either a high or low fat label compared 22 to no label. The data in Figure 2 suggested that weight-concerned participants of lowest SES 23 seemed to eat less in response to seeing either a high or low fat label compared to no label.…”

“…The high fat label dichotomised participants into those who saw 18 a high fat label and those who did not see a high fat label (that is saw a low fat label or no 19 label). The variables entered in each step of the model are shown in Table 1 20 To explore the research question assessing possible three-way interactions of label, BMI or 21 weight concern, and SES on consumption, four hierarchical multiple regressions were 22 conducted with consumption as the criterion variable and using the low and high fat dummy 23 variables. The variables entered in each step of the model are show in Table 1.…”

“…This 19 was done to minimise the response burden for a population with limited literacy and to 20 maintain the covert purpose of the study. In the context of a field experiment it was not 21 possible to accurately measure height and weight and thus these data were self reported, 22 which is known to be associated with underestimation of BMI. However, underestimation is 23 likely to be modest and unlikely to have affected the results of this experiment (Lin,DeRoo,24 Jacobs, & Sandler, 2011).…”

Associations of Maternal Material Hardships During Childhood and Adulthood with Prepregnancy Weight, Gestational Weight Gain, and Postpartum Weight Retention

“…The questionnaire inquiring about hardship has not been validated and could underestimate hardship exposure because of social stigma. We relied on self-reported prepregnancy weight, which may not be accurately reported; however, as we found and others have shown, [41][42][43] self-report tends to be highly correlated with measured weight, and thus ranking is likely to have been preserved across women. Furthermore, the prevalence of obesity, excessive GWG, and SPPWR were each similar to estimates from many other studies conducted around the same period.…”