Linguistic Validation of the Inflammatory Bowel Disease Questionnaire-Short Form (IBDQ-9) in Iranian Population

•Quality of life is significantly reduced in patients with inflammatory bowel disease (IBD). As there was no specific instrument for assessment of quality of life of Iranian IBD patients, we aimed to linguistically validate the Inflammatory Bowel Disease Questionnaire-Short Form (IBDQ-9) in Iranian IBD patients.• The IBDQ-9 was translated into Persian and culturally adapted following the standard forward-backward translation method. A sample of 100 IBD patients (50 Ulcerative Colitis and 50 Crohn’s Disease) completed the IBDQ-9, Short-Form-36 Health Survey (SF-36), Simplified Crohn’s Disease Activity Index (SCDAI), Simple Clinical Colitis Activity Index (SCCAI), and Hospital Anxiety and Depression Scale (HADS). Internal consistency was assessed using Cronbach’s alpha coefficient. To analyze the construct and discriminant validities, the IBDQ-9 and its subscales were correlated to SF-36 total and subscale scores and disease activity indices and HADS score, respectively.• The Cronbachs’ alpha coefficient of the IBDQ-9 was 0.76. There was significant correlations of the IBDQ-9 score with SF-36 total (r = 0.524, P < 0.001) and subscale scores (r = 0.476 to 0.541, P < 0.001). Also there was significant correlations of the IBDQ-9 score with SCDAI (r = -0.424, p = 0.025), SCCAI (r = -0.530, P < 0.001), and depression (r = -0.417, P < 0.001) and anxiety (r = -0.362, P < 0.001) scores.• The Persian version of the IBDQ-9 appears to be an appropriate instrument to assess quality of life of Iranian IBD patients. Further validation studies are warranted to investigate the reliability and validity of the IBDQ-9 after more editionslly.