Background: There is a need for easy-to-use patient-reported outcome measures (PROMS) in inflammatory bowel disease (IBD) practice. The 'IBD-control' is a short IBD-specific questionnaire capturing disease control from the patient's perspective. The International Consortium for Health Outcomes Measurement (ICHOM) recommends the use of the IBD-control even though it has only been validated in the United Kingdom. We aimed to cross-culturally translate and validate the IBD-control in the Netherlands using IBDREAM, a prospective multicentre IBD registry.
Methods: Lack of ambiguity and acceptability were verified in a pilot patient group (n = 5) after forward-backward translation of the IBD-control. Prospective validation involved completion of the IBD-control, Short Form-36, short IBDQ and disease activity measurement by Physician Global Assessment (PGA) and Simple Clinical Colitis Activity Index or Harvey-Bradshaw Index. Test-retest (2-week repeat) was used for measuring reliability.
Results: Questionnaires were completed by 998 IBD patients (674 Crohn's disease, 324 ulcerative colitis). Internal consistency (Cronbach's alpha) was 0.82 for the sub-group of 8 questions (IBD-control-8-sub-score). Mean completion time was 105 s. Construct validity analyses demonstrated moderate-to-strong correlations of the IBD-control-8-subscore and the other instruments (0.49-0.81). Test-retest reliability for stable patients was high (intraclass correlation coefficient 0.95). The IBD-control-8-subscore showed good discriminant ability between the PGA categories (ANOVA, p<.001). Sensitivity to change analyses showed large effect sizes of 0.81-1.87 for the IBD-control-8 subscore.
Conclusions: These results support the IBD-control as a rapid, reliable, valid and sensitive instrument for measuring disease control from an IBD patient's perspective in the Netherlands.
Keywords: Crohn’s disease; IBD-control; Inflammatory bowel disease; PROMs; ulcerative colitis.