Screening for eating disorders: false negatives and eating disorders not otherwise specified

RESUMEN

No disponible

ABSTRACT

Objective: To study the problem of false negatives in the screening for eating disorders. Subjects and Methods: We administered the Eating Attitudes Test (EAT40) and the Eating Disorder Inventory (EDI) to 186 Italian female students (age 17.68 ± 0.9; BMI 20.84 ± 2.69). Then we submitted not only high-scorers but also all the subjects to a semi-structured diagnostic interview (Eating Disorder Examination - EDE 12.0D). The diagnosis of eating disorders not otherwise specified (EDNOS) was applied to cases which met all the DSM-IV criteria for AN and/or BN with one exception. Results: 17 girls (9.1 percents) fulfilled diagnostic criteria for eating disorders 1 bulimia nervosa full-syndrome and 16 EDNOS. Of the 17 girls 11 were EAT low-scorers (< 30) and 8 were EDI low-scorers (< 50); 5 subjects scored below the cutoff on both instruments. We calculated sensitivity (35.3 percents), specificity (88.8 percents), positive predictive value (PPV, 24.0 percents) and negative predictive value (NPV, 93.2 percents) of the EAT40; the respective values for the EDI were 52.9 percents (sensitivity), 85.2 percents (specificity), 26.4 percents (PPV) and 94.7 percents (NPV). Discussion and Conclusion: Our data show that the introduction of the EDNOS diagnoses increases the PPV of the two questionnaires but lowers their sensitivity. We conclude that using a two stage screening approach leads to a very high rate of false negatives with a significant underestimation of the prevalence of eating disorders, particularly of EDNOS (AU)