Validade de peso, altura e índice de massa corporal autorreferidos na população adulta de Brasília

Abstract

Objective: To assess the validity of self-reported weight, height and body mass index (BMI) estimates from adults in Brasilia and to identify factors associated to differences between measured and self-reported values. Methods: In a cluster sampling 250 household ́s were selected and weight and height were measured in all adults after an interview. Bland & Altman (B&A) was used to determined agreement between measured and self-reported parameters. The multiple analysis of variance was used to determine the associated factors. Sensitivity and specificity were used for excess weight (BMI ≥ 25 kg/m2). Results: Interviews and measurements were done in 469 individuals. B&A showed bias (difference between measured and self-reported values) was not significant for weight (- 0.17 kg, p = 0.1) and significant for height (- 1 cm, p < 0.001). The limits of agreement (LA) were wide: from ± 4 kg for weight and - 6 cm to 4 cm for height. BMI presented a non significant bias of - 0.06 kg/ m2 (p = 0.08) and LA of - 1.5 to + 1.4 kg/m2. Men with a BMI < 25 kg/m 2 overestimated weight, while overweight or obese men underestimated it (p < 0.01). Men older than 60y of age (p = 0.037) and women with less than 12y of study (p < 0.01) overestimated height. The sensitivity and specificity to detect excess weight were for men and women, respectively: 94%, 88% and 90%, 98%. Sensitivity to detect excess weight was 77% for 60 or over years old women and 75% for women between 9 to 11 years of study, while. specificity was 78% for men between 30 e 39 years old. Conclusion: In Brasilia, self-reported height can be used for subgroups of women with more than 12y of study and men under 60y of age. Men with adequate BMI over estimate their weight when compared to overweight and obese men. Self-reported measures can be used for excess weight population follow-up.