Population at risk for eating disorders in a Spanish region.

OBJECTIVE: To estimate the prevalence of adolescent population at risk for eating disorders (EDs), to examine gender differences and their association with non-psychotic mental disorders. METHODS: Cross-sectional study using an anonymous, self-reported questionnaire in the classroom and measurement of weight and height in a representative sample of 4334 teenagers of both sexes. A definition of population at risk for EDs has been established, that differentiates those with dieting criteria and those with binge-purge eating behaviour criteria. This definition includes a combination of weight, behaviour, Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria, and Eating Disorder Inventory (EDI) results. The General Health Questionnaire-28 (GHQ-28) was used to assess non-psychotic mental disorders. RESULTS: The prevalence of population at risk for EDs was 2.2% (95% CI: 1.6-2.8) for men and 15.3% (95% CI: 13.8-16.9) for women. The prevalence rate of combining both ED risk and mental disorder was 0.8% (95% CI: 0.4-1.2) for men and 9.9% (95% CI: 8.6-11.2) for women. Non-psychotic mental disorders were more prevalent in the population at risk for EDs than in the rest of the population. CONCLUSIONS: A considerable proportion of adolescent females have eating problems and non-psychotic mental disorders. Their male counterparts also suffer from these disorders, however, a different pattern is followed.

Validación del peso y la talla autodeclarados en población adolescente / Validation of self-reported weight and height in an adolescent population

Fundamento: Examinar la relación entre el peso y la talla autodeclarados y las medidas antropométricas objetivas en la población adolescente, con objeto de evaluar su validez para poder estimar la prevalencia del índice de masa corporal (IMC) bajo (percentil 15) y elevado (percentil 85) en la población estudiada. Sujetos y método: La información del peso y la talla autodeclarados y objetivos se ha obtenido en una muestra representativa de 3.244 adolescentes entre 15 y 18 años escolarizados en centros de enseñanza secundaria de la Comunidad de Madrid. Se estima el error relativo medio, la correlación entre parámetros subjetivos y objetivos, así como la sensibilidad, la especificidad y el valor predictivo positivo de un IMC bajo y elevado. Resultados: El error relativo medio del peso es de un +0,07 por ciento en los varones y de un -0,79 por ciento en las mujeres. La estatura tiene un error medio de +0,51 y +0,98 por ciento en varones y mujeres respectivamente, y el del IMC de -0,88 y -2,63 por ciento. La correlación entre el IMC autodeclarado y objetivo es de 0,87 en los varones y de 0,90 en las mujeres. La prevalencia del IMC elevado se subestima un 34,1 por ciento en los hombres y un 34,4 por ciento en las mujeres. Por el contrario, la prevalencia del IMC bajo se sobrestima un 10,7 y un 14,8 por ciento en varones y mujeres, respectivamente. Conclusión: El análisis del IMC como variable continua, a partir de los datos de las medidas del peso y la talla autodeclarados, tiene poco margen de error. Su utilización como variable categórica conlleva una subestimación importante de la prevalencia de IMC elevado, y una sobrestimación de menor magnitud del IMC bajo (AU)

[Validation of self-reported weight and height in an adolescent population]. / Validación del peso y la talla autodeclarados en población adolescente.

INTRODUCTION: The aim of this study was to examine the relationship between self-reported population in order to evaluate the validity of self-reported measures for the purpose of estimating the prevalence of low (less-than-or-equal 15th percentile) and high (greater-than-or-equal 85th percentile) body mass index (BMI) in the study population. SUBJECTS AND METHOD: Information on self-reported and objective weight and height was obtained from a representative sample of 3,244 adolescents, aged 15-18 years, in secondary education schools in the Autonomous Community of Madrid. We calculated the mean relative error; the correlation between subjective and objective parameters, sensitivity, specificity and predictive value positive of low and high BMIs. RESULTS: The mean relative errors were as follows: weight: +0.07% for males versus and 0.79% for females; height, +0.51% for males versus +0.98% for females; BMI: 0.88% for males versus 2.63% for females. The correlation between self-reported and objective BMI was 0.87 for males and 0.90 for females. The prevalence of high BMI was underestimated by 34.1% and 34.4% of females white that of low BMI was overestimated by 10.7% of males and 14.8% of females. CONCLUSION: Analysis of BMI as a continuous variable, based on self-reported weight and height measurement data, entails a small margin of error. However, its use as a categorical variable involves a considerable underestimate of the prevalence of high BMI, and an smaller overestimate of the prevalence of low BMI.