The Psychometric Properties of Night Eating Questionnaire in Schizophrenic Outpatients

Lee, Se Young; Yoon, Bo Hyun; Sea, Young Hwa; Park, Soo Hee; Bae, Ahn

Abstract

OBJECTIVES
The purpose of this study was to evaluate the psychometric properties of the Night Eating Questionnaire (NEQ) as a measure of the night eating syndrome (NES) in a sample of outpatients with schizophrenia.
METHODS
The behavioral and psychological symptoms of NES were assessed with the 14-item self-report questionnaire (NEQ). Body weight and height were measured to calculate the body mass index (BMI). Subjective estimates of depression, binge eating patterns, sleep quality and weight-related quality of life were evaluated using Beck's Depression Inventory (BDI), the Binge Eating Scale (BES), the Pittsburgh Sleep Quality Index (PSQI) and the Korean version of Obesity-related Quality of Life (KOQoL) Scale.
RESULTS
Among 165 schizophrenic outpatients who completed the NEQ, 15 (9.1%) patients screened as having NES (total NEQ > or =25). The NEQ demonstrated high internal consistency (Cronbach's alpha=0.72), and the item-total correlations (r=0.29-0.75 ; p<0.001, respectively) were acceptable, except for morning anorexia. A principal components analysis revealed five factors (nocturnal ingestions, evening hyperphagia, mood/sleep, morning anorexia, and delayed morning meal), which explained 65.7% of the total variance. Although the NEQ total score was not correlated with BMI, age at onset, duration of illness, or use of atypical antipsychotics, it was significantly correlated with total scores on the BDI, BES, PSQI and KOQoL. Test-retest reliability was also good (r=0.74, p<0.001).
CONCLUSION
Our results showed that the NEQ appears to be an efficient, valid measure of NES in outpatients with schizophrenia.