Multi-item Measures for Paediatric Inflammatory Bowel Diseases: The ABCs of All Those Acronyms

With the recent acceptance of multiple treatment goals for inflammatory bowel diseases [IBD], it becomes increasingly important to accurately quantify the measurable concepts. These include patient-reported symptoms, intestinal damage, mucosal activity, transmural inflammation, and histologicl appearance, as well as quality of life, disability, and other patient-centred attributes. Standardised indices which show sufficient validity, reliability, and responsiveness to change are not only mandatory for implementing the treat to target approach but are also critical for assessing the effectiveness of emerging medications in clinical trial settings. Some concepts can be accurately assessed through the use of existing measurement tools used for adults [eg, capsule endoscopy, ultrasonic, endoscopic, and histological scoring] and others may be age specific. Although several paediatric indices and scales are well established (eg, IMPACT questionnaire, Paediatric Crohn's Disease Activity Index [PCDAI], and Paediatric Ulcerative Colitis Activity Index [PUCAI]), recent years have seen the development of newer indices for children, including the Mucosal Inflammation Noninvasive Index [MINI] to predict endoscopic healing in Crohn's disease, magnetic resonance imaging [MRI] indices that measure inflammation (ie, the Paediatric Inflammatory Crohn's Magnetic Resonance Enterography Index [PICMI]) and perianal disease (ie, Paediatric MRI-based Perianal Crohn's Disease [PEMPAC]), and patient-reported outcome measures in ulcerative colitis [ie, TUMMY-UC], upper gastrointestinal inflammatory score [ie, UGI-SES-CD], simplified endoscopic mucosal assessment score for Crohn's disease [SEMA-CD], and the parent-completed IMPACT questionnaire [ie, IMPACT-III-P]. Despite these advances, quantifiable paediatric IBD-specific tools are still lacking for disability and fatigue. In this review, we provide a contemporary, clinically focused overview of the indices that a paediatric gastroenterologist can use to quantify disease status.