Validation of the Interpersonal Relationships in Eating Disorders (IR‐ED) Scale in an Eating Disorder Sample

Abstract

ObjectiveInterpersonal problems have been identified as a plausible mechanism underlying the onset and maintenance of eating disorders. The Interpersonal Relationships in Eating Disorders (IR‐ED) scale is the first eating disorders‐specific measure of interpersonal problems, which was developed in a nonclinical sample. The aims of the current study were to (a) confirm the factor structure of the IR‐ED within a large clinical sample, (b) investigate measurement invariance of the IR‐ED across nonclinical and clinical samples, (c) examine the convergent validity of the IR‐ED using a generic measure of interpersonal problems, and (d) investigate the incremental clinical utility of the IR‐ED in uniquely predicting eating disorder symptomatology.MethodTreatment‐seeking individuals (N = 437) completed the IR‐ED at their initial assessment appointment at a specialist eating disorder outpatient service.ResultsA multiple‐group confirmatory factor analysis supported an invariant bifactor structure comprising a general interpersonal problems factor and two group factors—Avoidance of Body Evaluation and Food‐Related Interpersonal Tension. Convergent validity was demonstrated by a large, statistically significant correlation with a generic measure of interpersonal problems (r = 0.62, p < 0.001). A series of structural equation models further revealed unique incremental predictive utility of the IR‐ED for eating disorder symptomatology.DiscussionThe IR‐ED has strong psychometric properties and may prove beneficial in the assessment, formulation, and treatment of eating‐specific interpersonal problems among patients with eating disorders.