Interrater reliability and internal consistency of the eating disorder examination in the longitudinal assessment of bariatric surgery study

Abstract

Background: Psychometric studies of eating disorder measures within bariatric surgery populations are limited.

Objectives: To examine the interrater reliability and internal consistency of the Eating Disorder Examination (EDE) among patients before and after bariatric surgery.

Setting: Three clinical centers of the Longitudinal Assessment of Bariatric Surgery Research Consortium.

Methods: The EDE-Bariatric Surgery Version was administered and audio-recorded by trained interviewers before and at annual assessments after bariatric surgery. Approximately 20% of interviews were randomly selected for rating by a second interviewer. Reliability of the original and brief EDE subscales was examined.

Results: Interrater reliability of the EDE subscales ranged from .86-.97 for the original subscales and .83-.95 for brief subscales before surgery, and .90-.98 for the original subscales and .92-.97 for brief subscales after bariatric surgery. Interrater agreement (based on kappa) was almost perfect for overeating and binge-eating behaviors and substantial for loss-of-control eating before surgery. Similar interrater agreements (based on kappa) were observed after surgery for subjective overeating and binge-eating episodes. Internal consistency of the subscale and global scores was variable, ranging from .41-.97.

Conclusion: Findings provide support of the interrater reliability of the EDE, albeit with variable internal consistency, before and after bariatric surgery. Despite support for trained raters to reliably assess EDE constructs, variability in internal consistency suggests that further psychometric testing and rigorous scale development of disordered eating may be needed for the bariatric surgery population.

Keywords: Bariatric surgery; Feeding and eating disorders; Gastric bypass; Obesity; Psychometrics; Reproducibility of results; Weights and measures.