Agreement between measured and self-reported height, weight and BMI in predominantly European middle-aged New Zealanders: findings from a nationwide 1989 survey

N Z Med J. 2012 Sep 21;125(1362):60-9.

Abstract

Aim: To examine the agreement between self-reported and measured height, weight and BMI in 40-50 year old New Zealand men and women.

Method: Self-reported and measured height, weight and derived BMI were examined using data from 345 40-50 year old participants in the 1989/1990 Life In New Zealand Survey. Factors associated with biased reporting were assessed using regression models.

Results: Height was overestimated by men (1.08 cm, 95%CI 0.58, 1.59 p<0.001) and women (0.61 cm, 95%CI 0.35, 0.87, p<0.001), contributing to a small but statistically significant underestimation of BMI (men 0.31 kg/m2, 95%CI 0.14, 0.48, p<0.001; women 0.26 kg/m2 95%CI 0.11, 0.41, p<0.001). Weight was not statistically significantly misestimated by either sex. Bias in self-reported BMI did not differ by age, sex, ethnicity, SES or measured BMI category (all p-values <0.231). Agreement between BMI categories based on self-reported and measured data was very good (kappa: men 0.80, women 0.93).

Conclusion: Self-reported height and weight from New Zealand 40-50 year olds in 1989 produced BMI estimates valid for use in epidemiological studies, especially when used as a continuous variable. Our analyses need to be replicated using data from a current and representative New Zealand sample.

MeSH terms

  • Adult
  • Attitude to Health
  • Body Height*
  • Body Mass Index*
  • Body Weight*
  • European Continental Ancestry Group / statistics & numerical data*
  • Female
  • Health Status
  • Humans
  • Male
  • Mass Screening / statistics & numerical data*
  • New Zealand / epidemiology
  • Obesity / diagnosis
  • Obesity / epidemiology*
  • Reference Values
  • Reproducibility of Results
  • Self Concept
  • Self Disclosure*
  • Young Adult