Short Inflammatory Bowel Disease Questionnaire: translation and validation to the Portuguese language

BackgroundThe Short Inflammatory Bowel Disease Questionnaire (SIBDQ) is a widely used instrument to assess Health-related Quality of Life (HRQoL) among inflammatory bowel disease (IBD) patients. Our aim was to translate and adapt the SIBDQ so that it could be adequately used in Portugal. MethodsThis is a prospective design cohort study undertaken at a tertiary hospital. This study took place simultaneously with the first part of the SexIDI study, a study aiming to assess the impact of IBD on patients' sexual QoL. The original SIBDQ was translated by two independent translators and adapted by an IBD expert panel following the opinions of a convenient sample of 5 IBD patients. Afterwards, IBD patients from the outpatient clinic were consecutively invited to fill the Portuguese version of the questionnaire (SIBDQ-PT) at three different timepoints (0, 2, 4 weeks). Ninety-two patients completed the SIBDQ-PT at baseline, whereas 33 did so after 2 and 4 weeks (approximately). Statistical analysis was performed using SPSS version 25, and the following aspects were analysed: reliability (through internal consistency, test-retest and intraclass correlation), validity (through exploratory factor analysis [EFA], and Pearson correlation coefficient for linear correlations), score distribution, and responsiveness analysis (through t-student tests).ResultsOverall, SIBDQ-PT was shown to have a high internal consistency (Cronbach's alpha =0.80) and a high test-retest reliability (0.80 [CI 0.74-0.86] and 0.69 [CI 0.50-0.82]). EFA detected four dimensions-bowel, social, emotional and systemic. As expected, an overall SIBDQ-PT score was positively correlated with sexual satisfaction (r=0.27; p<0.05) and negatively correlated with depression (r=-0.63; p<0.01). Moreover, SIBDQ-PT was found to have an adequate score distribution, and to be responsive, as there was a significant subscore change for patients who reported an "overall worsening in general well-being" (0.930.13 decrease; p<0.01).Conclusions The Portuguese version of the SIBDQ hereby presented is a reliable, valid and responsive instrument that can be used to measure HRQoL among Portuguese IBD patients.