Estimating equations to correct self-reported height and weight: implications for prevalence of overweight and obesity in Australia.
OBJECTIVE
To derive correction equations based on nationally representative data, for the error associated with self-reported height and weight and to apply these to recent estimates of overweight and obesity in the Australian adult population.


METHODS
Linear regression was used to derive correction equations to predict reporting error on height, weight and body mass index (BMI) for 8,435 adults, aged 20 and over, who had their height and weight accurately measured as participants of the 1995 National Nutrition Survey (NNS) and who had also supplied self-reported information within the 1995 National Health Survey (NHS).


RESULTS
Evaluation of different correction algorithms suggests that simple correction equations for height and weight (each with one independent variable) are the most useful in the prediction of corrected prevalence of overweight and obesity. Applying these equations to nationally representative data suggests that the prevalence of overweight and obesity (BMI > or = 25) in Australia in 2004/05 was 66% compared with the value of 54% determined from self-reported data.


CONCLUSIONS
We present a simple and reliable method for correcting true prevalence of overweight and obesity from self-reported data.


CONCLUSIONS
In order to get realistic estimates of overweight and obesity in Australia, either measured height and weight data should be collected directly, or equations to correct for self report error should be used.
Hayes
Alison J
AJ
School of Public Health, University of Sydney, New South Wales 2006, Australia. alisonh@health.usyd.edu.au
Kortt
Michael A
MA
Clarke
Philip M
PM
Brandrup
Jason D
JD
D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001315:Australia / Q000453:epidemiology; D001827:Body Height / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology; D015995:Prevalence; D012044:Regression Analysis; D013223:Statistics as Topic; D055815:Young Adult