Health-related quality of life assessment in eating disorders: adjustment and validation of a specific scale with the inclusion of an interpersonal domain

Abstract

Purpose: Quality of life is a fundamental aspect of both clinical practice and research on eating disorders (ED) due to the significant impacts these disorders have on everyday life. Disorder-specific scales can improve the quality of research and findings and offer greater sensitivity and responsiveness. However, no specific instrument is available in Italian for ED. The aim of this paper is to adjust and to validate a reliable scale with specific items regarding physical and interpersonal well-being.

Methods: The Italian version of the Eating Disorder Quality of Life (IEDQOL) scale was developed, on the basis of the original English scale, with the addition of items pertaining to physical well-being and interpersonal interactions. In this study, 180 ED patients and 190 healthy controls from the community were enrolled both from inpatient units and outpatient services. A statistical analysis with an exploratory factorial approach was performed in order to validate the tool.

Results: The results showed that the IEDQOL has very good psychometric properties with test-retest validity and sensitivity between patients and controls (d = 2.17 for total score). Moreover, the interpersonal domain showed excellent psychometric values (Cronbach's α > 0.70 in all the subgroups) and a robust correlation with other quality of life constructs.

Conclusion: Future studies on the Italian population should use IEDQOL as outcome element that can be useful also with other disorder-specific psychopathological constructs and corroborate the reliability of the data. Future research in the ED field should only use this specific tool.

Level of evidence: Case-control analytic study, Level III.

Keywords: Anorexia Nervosa; Binge Eating Disorder; Bulimia Nervosa; Eating Disorders; Health-related quality of life; Interpersonal domain.