A comparison of measured height and demi-span equivalent height in the assessment of body mass index among people aged 65 years and over in England.

Objectives: to examine differences between measured height and demi-span equivalent height (DEH) among people aged >or=65 and investigate the impact on body mass index (BMI) of using DEH.

Design And Setting: nationally representative cross-sectional sample of adults living in England.

Participants: 3,346 non-institutionalised adults aged >or=65, taking part in the Health Survey for England (HSE) 2001.

Measurements: height, weight and demi-span measurements were taken according to standardised HSE protocols. DEH was calculated using Bassey's equation.

Results: the height measurement was lower than the DEH from age group 70-74 years onwards in men and in each age group in women. No significant differences in mean DEH and measured height were found for men (-0.46) or women (-2.64). BMI derived from measured height did not differ significantly from BMI derived from DEH. The prevalence of underweight was lower when using measured height than when using DEH in women aged >or=65, particularly in those aged 80 years and over. The prevalence of overweight and obesity was higher using measured height than DEH in women aged >or=65.

Conclusion: we confirmed in a large nationally representative sample that demi-span measurement may be a useful estimate of stature in people (particularly women) aged >or=65 for BMI calculations.