Validation of the Persian version of the inflammatory bowel disease questionnaire (IBDQ) in ulcerative colitis patients

BACKGROUND Inflammatory bowel diseases (IBD) are a group of inflammatory conditions of the colon and small intestine that may have critical consequences on patient's quality of life (QOL). Many disease-specific QOL tools have been developed recently. The McMaster Inflammatory Bowel Disease Questionnaire (IBDQ) is one of them. The aim of this study was to translate the IBDQ from English to Persian and evaluate the validity and reliability of this version of the McMaster IBDQ. METHODS 68 subjects with ulcerative colitis were recruited in this study. The original IBDQ was translated into Persian using back- translation method. The reliability of the subscales and the summary score of the Persian IBDQ was demonstrated by intraclass correlation coefficients, their validity was evaluated by their correlations with SF-36, visual analogue scale and colitis activity index. RESULTS All dimensions of IBDQ met the standards of construct validity and were correlated well with SF-36, visual analog scale and colitis activity index. IBDQ was able to discriminate the different groups of patients. The intraclass correlation coefficient was very high and its value was close to one (P<0.05). All dimensional scores differed significantly between the baseline and the follow-up measurement. CONCLUSION The findings of this study conclude that the Persian translation of IBDQ confers satisfactory psychometric and cultural properties when applied to a sample of Iranian population with inflammatory bowel disease. This questionnaire is recommended for use in clinical trials and in the assessment of efficacy of interventions and therapy.