Reliability, Validity, and Transcultural Adaptation of New Persian Version of Celiac Disease Quality of Life Questionnaire.

Background: Health-related quality of life (HRQOL) assessment in patients with celiac disease (CD) leads to understanding the impact of the CD and interventions on the individual and society. The aim of this study was transcultural adaptation and evaluation of the reliability and validity of the standardized questionnaire of celiac disease quality of life (CD-QOL) in the Persian language in southwest Iran. Methods: 150 adults with CD were randomly selected from the celiac clinic and Fars Celiac Registry to complete the New Persian version of the CD-QOL questionnaire. Transcultural adaptation of the questionnaire was conducted by a four-step procedure. The internal consistency of the CD-QOL subscales and convergent and discriminant validity were assessed using Cronbach's alpha coefficient and Spearman's correlation, respectively. Construct validity was evaluated by exploratory and confirmatory factor analysis. Results: All domains of the CD-QOL questionnaire had acceptable internal consistency, showing excellent reliability. The scaling success rates for convergent and discriminant validity were also within an acceptable range (87-100%). In the factor analysis model, similar to the original English version, four factors were extracted characterizing the patients' answers (limitations, dysphoria, health concerns, and inadequate treatment). Conclusion: Our Persian version of the CD-QOL questionnaire had high reliability and validity and could be used in clinical practice assessing the CD-specific HRQOL in the Iranian population.