Factor Structure and Measurement Invariance Across Gender of the Eating Disorder Examination Questionnaire—Short Form in Italian Workers

TL;DR

This study evaluates the Italian version of a questionnaire for eating disorders in workers, finding it reliable but with some gender-related differences.

Contribution

The study provides evidence for the structural validity of the Italian EDE-QS in occupational settings and identifies gender-related item bias.

Findings

The Italian EDE-QS shows a unidimensional structure with high internal consistency and strong construct replicability.

Measurement invariance was partial, with differential item functioning observed in some items between genders.

Women scored slightly higher than men, but overall associations with variables were consistent across genders.

Abstract

Eating disorders (EDs) are complex conditions that can significantly affect health and productivity, yet their assessment in occupational settings remains underexplored. This study aimed to evaluate the psychometric properties of the Italian version of the Eating Disorder Examination Questionnaire—Short Form (EDE-QS) among 1912 workers undergoing health surveillance. Using an Item Response Theory framework, we tested dimensionality, reliability, and measurement invariance across gender, applying a graded response model to assess item discrimination and threshold parameters. Results supported an approximate unidimensional structure with excellent internal consistency (ω ≈ 0.95) and strong indices of factor score determinacy and construct replicability. Measurement invariance analyses indicated configural and metric invariance but not full scalar invariance, due to differential item functioning in a subset of items. Latent mean differences were small, with women scoring slightly higher than men, and associations with psychological, occupational, and health-related variables did not differ by gender. These findings indicate that the Italian EDE-QS shows promising structural validity as a brief measure of ED symptomatology in occupational samples in workplace contexts. However, gender-related item bias warrants cautious interpretation of specific behaviors, suggesting the need for tailored assessments to enhance diagnostic accuracy and inform preventive interventions.

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