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.

[Validation of self-reported weight and height in an adolescent population]

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.