[Validity of self-reported weight and height: the Goiânia study, Brazil].
OBJECTIVE
To assess the validity of self-reported weight and height at the time of diagnosing obesity, and to identify the sociodemographic and individual characteristics that might be a source of information bias.


METHODS
This was a cross-sectional population-based study carried out in the city of Goiânia in 2001. Interviews were conducted with 1,023 individuals aged 20-64 years, in their homes, to collect sociodemographic and self-reported weight and height information. On the same occasion, weight and height measurements were made on these individuals. The mean differences and correlation coefficients between self-reported and measured data were calculated according to age, body mass index (BMI), schooling, income and height.


RESULTS
Both the men and women overestimated their heights (p<0.05), by 0.9 cm and 2.2 cm, respectively. There was no difference between self-reported and measured weights, either for the men (-0.44 kg; p=0.06) or for the women (-0.03 kg; p>0.05). The behavior of overestimating height was influenced by age, schooling, height and body mass index. Although this index obtained from the self-reported data was underestimated (p<0.05), by 0.27 kg/m(2) and 0.67 kg/m(2) for men and women respectively, the measured and self-reported data presented a high degree of agreement. Both the sensitivity and specificity of the self-reported body mass index were high, in relation to identifying the measured index.


CONCLUSIONS
In epidemiological studies for monitoring the prevalence of excess weight in populations, self-reported weights and heights constitute reliable data, which gives validity to the methodology utilized.
Peixoto
Maria do Rosário Gondim
Mdo R
Faculdade de Nutrição, Universidade Federal de Goiás, Goiânia, GO, Brasil. hbpeixoto@uol.com.br
Benício
Maria Helena D'Aquino
MH
Jardim
Paulo César Brandão Veiga
PC
D000328:Adult; D000367:Age Factors; D015982:Bias; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D001938:Brazil / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology*; D015203:Reproducibility of Results; D012649:Self Concept; D012737:Sex Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires / Q000592:standards*