Purpose: The aim of this study was to develop a Korean version of Night Eating Questionnaire (KNEQ) and test its psychometric properties and evaluate items according to item response theory.
Methods: The 14-item NEQ as a measure of severity of the night eating syndrome was translated into Korean, and then this KNEQ was evaluated. A total of 1171 participants aged 20 to 50 completed the KNEQ on the Internet. To test reliability and validity, Cronbach's alpha, correlation, simple regression, and factor analysis were used. Each item was analyzed according to Rasch-Andrich rating scale model and item difficulty, discrimination, infit/outfit, and point measure correlation were evaluated.
Results: Construct validity was evident. Cronbach's alpha was .78. The items of evening hyperphagia and nocturnal ingestion showed high ability in discriminating people with night eating syndrome, while items of morning anorexia and mood/sleep provided relatively little information. The results of item analysis showed that item2 and item7 needed to be revised to improve the reliability of KNEQ.
Conclusion: KNEQ is an appropriate instrument to measure severity of night eating syndrome with good validity and reliability. However, further studies are needed to find cut-off scores to screen persons with night eating syndrome.
Keywords: Eating disorder; Psychometrics; Questionnaire; Self-report.