Consistency between anthropometric measures in national surveys

To analyze the consistency between height and weight values obtained by direct measurement and reporting in contemporary national surveys.

A group of 20 to 39 year olds were selected in the Household Budget Survey (POF) and Surveillance System Risk and Protective Factors for Chronic Diseases Survey Telephone (VIGITEL), 2008 and 2009. The surveys were matched by sex and age. For inference about the comparison between standardized (POF) and self-declared (VIGITEL) height and weight values used the Student t test and the Spearman estimator (ρ). The consistency between anthropometric indexes and indicators in the two surveys was estimated by the estimators of Lin (Φ) and Pearson (r).

Weight and height results were higher than those measured in a standardized way. The correlation of average height in the two surveys was ρ = 0.31 in women and ρ = 0.62 in men. The association was ρ = 0.86 and 0.88 respectively, for weight. Body mass index showed a strong correlation and agreement of approximately 0.90 for the two estimators in both sexes. The agreement between the diagnosis of obesity from the values of the measured and self-declared surveys was Φ = 0.89 in men and Φ = 0.91 in women.

Reported height and weight follow the same bias as those measured standardly and eliminates distortion in estimated indices and indicators in both surveys. The declared anthropometric values show good prospects for use in other analyses involving determinants of health and nutrition.