How valid are self-reported height and weight? A comparison between CATI self-report and clinic measurements using a large cohort study
Version of Record online: 26 SEP 2007
Australian and New Zealand Journal of Public Health
Volume 30, Issue 3, pages 238–246, June 2006
How to Cite
Taylor, A. W., Grande, E. D., Gill, T. K., Chittleborough, C. R., Wilson, D. H., Adams, R. J., Grant, J. F., Phillips, P., Appleton, S. and Ruffin, R. E. (2006), How valid are self-reported height and weight? A comparison between CATI self-report and clinic measurements using a large cohort study. Australian and New Zealand Journal of Public Health, 30: 238–246. doi: 10.1111/j.1467-842X.2006.tb00864.x
- Issue online: 26 SEP 2007
- Version of Record online: 26 SEP 2007
- Revision requested: December 2005 Accepted: February 2006
Objective: To examine the relationship between self-reported and clinical measurements for height and weight in adults aged 18 years and over and to determine the bias associated with using household telephone surveys.
Method: A representative population sample of adults aged 18 years and over living in the north-west region of Adelaide (n=1,537) were recruited to the biomedical cohort study in 2002/03. A computerassisted telephone interviewing (CATI) system was used to collect self-reported height and weight. Clinical measures were obtained when the cohort study participants attended a clinic for biomedical tests.
Result: Adults over-estimated their height (by 1.4 cm) and under-estimated their weight (by 1.7 kg). Using the self-report figures the prevalence of overweight/ obese was 56.0% but this prevalence estimate increased to 65.3% when clinical measurements were used. The discrepancy in self-reported height and weight is partly explained by 1) a rounding effect (rounding height and weight to the nearest 0 or 5) and 2) older persons (65+ years) considerably over-estimating their height.
Conclusion: Self-report is important in monitoring overweight and obesity; however, it must be recognised that prevalence estimates obtained are likely to understate the problem.
Implications: The public health focus on obesity is warranted, but self-report estimates, commonly used to highlight the obesity epidemic, are likely to be underestimations. Self-report would be a more reliable measure if people did not round their measurements and if older persons more accurately knew their height.