Measuring the accuracy of self-reported height and weight in a community-based sample of young people

BACKGROUND: Self-reported anthropometric data are commonly used to estimate prevalence of obesity in population and community-based studies. We aim to: 1) Determine whether survey participants are able and willing to self-report height and weight; 2) Assess the accuracy of self-reported compared to measured anthropometric data in a community-based sample of young people.

METHODS: Participants (16-29 years) of a behaviour survey, recruited at a Melbourne music festival (January 2011), were asked to self-report height and weight; researchers independently weighed and measured a sub-sample. Body Mass Index was calculated and overweight/obesity classified as ≥25 kg/m². Differences between measured and self-reported values were assessed using paired t-test/Wilcoxon signed ranks test. Accurate report of height and weight were defined as <2 cm and <2 kg difference between self-report and measured values, respectively. Agreement between classification of overweight/obesity by self-report and measured values was assessed using McNemar's test.

RESULTS: Of 1405 survey participants, 82% of males and 72% of females self-reported their height and weight. Among 67 participants who were also independently measured, self-reported height and weight were significantly less than measured height (p=0.01) and weight (p<0.01) among females, but no differences were detected among males. Overall, 52% accurately self-reported height, 30% under-reported, and 18% over-reported; 34% accurately self-reported weight, 52% under-reported and 13% over-reported. More females (70%) than males (35%) under-reported weight (p=0.01). Prevalence of overweight/obesity was 33% based on self-report data and 39% based on measured data (p=0.16).

CONCLUSIONS: Self-reported measurements may underestimate weight but accurately identified overweight/obesity in the majority of this sample of young people.

The contribution of workplace characteristics to the risk of Type 2 Diabetes

Diabetes has a significant economic impact on individuals, families, health systems, and countries [1]. In 2010 it was estimated that the global health expenditure on diabetes was US376 billion (€292 billion), equating to 12% of health expenditure and US1330 (€1031) per person [2]. A separate estimate in 2010 reported that diabetes cost the US US174 billion (€135 billion), with US58 billion (€45 billion) in indirect costs equating to over US2000 (€1551) on average per person with diabetes [3]. The World Health Organization estimates that between 2005 and 2030 the proportion of deaths caused by diabetes will double and global health expenditures associated with diabetes are expected to reach US490 billion (€380 billion) [1,2]. In 2003, it was estimated that diabetes cost Australia AUS6 billion (US6 billion, €5 billion), with AUS21 million (US22 million, €17 million) in indirect costs such as lost workdays and lost productivity equating to approximately AUS35 (US35, €28) per person with diabetes [4].