Transcultural adaptation of the Night Eating Questionnaire (NEQ) for its use in the Spanish population

Background: Establishing valid and reliable methods of assessing night eating symptoms is an important goal to maximize identification and treatment of the night eating syndrome (NES). The 14-item Night Eating Questionnaire (NEQ) is the only published and validated assessment instrument but is not yet adapted to Spanish.

Methods: We examined the factor structure, internal consistency and validity of the NEQ in Spanish. The study had 4 phases: a) translation from English to Spanish; b) back-translation from Spanish to English, c) administration of translated version to a Spanish sample, and d) a re-test in 36 participants two weeks later. Reliability, stability, and scale structure were evaluated by Cronbach's α, test-re-test, and factor analysis, respectively. Divergent validity was assessed by correlation with the Spanish versions of the State-Trait Anxiety Inventory (STAI) and the Beck Depression Inventory (BDI-II).

Results: Two-hundred forty-four individuals (181 f; BMI 34.3±10 kg/m(2); age 40.5±15 y) completed the questionnaire. The mean NEQ score was 12.5±7. The Cronbach's α coefficient for the total score was 0.79, the intraclass correlation was 0.85, and the factor analysis yielded a similar four factor solution as the original scale. Correlation for the test-re-test total score was 0.86. Total NEQ score was significantly correlated with the BDI-II (r=0.48 p<0.001), but this correlation was not significant during the test-re-test (r=0.28, p=0.10) or with STAI at either time point (0.05, p=0.40; r=0.07, p=0.69, respectively).

Conclusions: The Spanish version of the NEQ demonstrated adequate internal consistency for the majority of domains and excellent reproducibility. There was divergent validity with anxiety and a relationship between night eating and depression. These results suggest that the Spanish-version of the NEQ is an instrument that is valid for use in clinical research.