Validation of the eating disorders inventory in a nonclinical population using transformed and untransformed responses.

In the present study, the validity of the Eating Disorder Inventory (EDI) in a Dutch nonclinical female school population was established. The data were analyzed in two ways. In the first analyses, the factorial integrity of the questionnaire, and the internal consistencies of the subscales were not found to be very satisfactory. The data showed an impressive lack of variability. It was suggested by the authors that in a nonclinical population the variability of the EDI data is being suppressed as a result of the fact that, in concordance with the manual, the original 6-point EDI items were transformed into 4-point items. In the second analyses, this item transformation was ejected. The psychometric properties of all EDI subscales in the present study improved. Implications for the use of the untransformed EDI as a screening instrument were discussed.