Recommendations for Standardizing MRI-based Evaluation of Perianal Fistulizing Disease Activity in Pediatric Crohn's Disease Clinical Trials.

BACKGROUND: Perianal fistulas and abscesses occur commonly as complications of pediatric Crohn's disease (CD). A validated imaging assessment tool for quantification of perianal disease severity and activity is needed to evaluate treatment response. We aimed to identify magnetic resonance imaging (MRI)-based measures of perianal fistulizing disease activity and study design features appropriate for pediatric patients. METHODS: Seventy-nine statements relevant to MRI-based assessment of pediatric perianal fistulizing CD activity and clinical trial design were generated from literature review and expert opinion. Statement appropriateness was rated by a panel (N = 15) of gastroenterologists, radiologists, and surgeons using modified RAND/University of California Los Angeles appropriateness methodology. RESULTS: The modified Van Assche Index (mVAI) and the Magnetic Resonance Novel Index for Fistula Imaging in CD (MAGNIFI-CD) were considered appropriate instruments for use in pediatric perianal fistulizing disease clinical trials. Although there was concern regarding the use of intravascular contrast material in pediatric patients, its use in clinical trials was considered appropriate. A clinically evident fistula tract and radiologic disease defined as at least 1 fistula or abscess on pelvic MRI were considered appropriate trial inclusion criteria. A coprimary clinical and radiologic end point and inclusion of a patient-reported outcome were also considered appropriate. CONCLUSION: Outcomes of treatment of perianal fistulizing disease in children must include MRI. Existing multi-item measures, specifically the mVAI and MAGNIFI-CD, can be adapted and used for children. Further research to assess the operating properties of the indices when used in a pediatric patient population is ongoing.

Reliability and Responsiveness of Histologic Indices for the Assessment of Crohn's Disease Activity.

BACKGROUND & AIMS: The operating properties of histologic indices for evaluating Crohn's disease (CD) activity are poorly characterized. We assessed the reliability and responsiveness of existing histologic indices/items used in CD and ulcerative colitis (UC), in addition to 3 novel items, and developed exploratory ileal, colonic, and colonic-ileal CD instruments. METHODS: Blinded central readers independently reviewed paired baseline and week 12 image sets from the EXTEND trial. Disease activity was scored using 4 indices (the Global Histologic Activity Score, Geboes Score, Nancy Histological Index, and Robarts Histopathology Index) and 3 items identified by an expert panel (mucin depletion, basal plasmacytosis, and ileal pyloric gland metaplasia). Reliability and responsiveness were quantified using the intraclass correlation coefficient (ICC) and area under the receiver operating curve (AUC), respectively. Exploratory indices were developed using backward stepwise linear regression analysis. Candidate independent variables were items with an inter-rater ICC ≥0.40 and AUC ≥0.56. The dependent variable was histologic disease activity measured by a 100-mm visual analogue scale. RESULTS: Paired image sets were available from 55 patients. Substantial to almost perfect inter-rater reliability (ICC, 0.63-0.87) and some responsiveness (AUC, 0.57-0.94) were observed for all existing indices regardless of whether individual colonic and ileal segments, combined colonic segments, or combined colonic and ileal segments were assessed and the calculation method used. Five items were tested as candidate items, and exploratory colonic, ileal, and colonic-ileal indices were developed. CONCLUSIONS: CD and UC indices were similarly reliable and responsive in measuring histologic CD activity. Exploratory index development did not offer benefit over current histologic instruments.

Standardizing Scoring Conventions for Crohn's Disease Endoscopy: An International RAND/UCLA Appropriateness Study.

BACKGROUND AND AIMS: Endoscopic assessment of disease activity is integral for evaluating treatment response in patients with Crohn's disease (CD). We aimed to define appropriate items for evaluating endoscopic activity and conventions for consistent endoscopic scoring rules in CD. METHODS: A 2-round modified RAND/University of California at Los Angeles Appropriateness Method study was conducted. A panel of 15 gastroenterologists used a 9-point Likert scale to rate the appropriateness of statements pertaining to the Simple Endoscopic Score for CD, Crohn's Disease Endoscopic Index of Severity, and additional items relevant to endoscopy scoring in CD. Each statement was voted as appropriate, uncertain, or inappropriate based on the median panel rating and presence of disagreement. RESULTS: Panelists voted that it is appropriate for all ulcers to contribute to endoscopic scoring in CD, including aphthous ulcers, ulcerations at a surgical anastomosis, and anal canal ulcers (scored in the rectum). Endoscopic healing should reflect an absence of ulcers. Narrowing should be defined as a clear decrease in luminal diameter; stenosis should be defined by an impassable narrowing, and if occurring at the junction of 2 segments, scored in the distal segment. Scarring and inflammatory polyps were considered inappropriate for including in the affected area score. The optimal method for defining ulcer depth remains uncertain. CONCLUSIONS: We outlined scoring conventions for the Simple Endoscopic Score for CD and Crohn's Disease Endoscopic Index of Severity, noting that both scores have limitations. Therefore, we identified priorities for future research and steps for developing and validating a more representative endoscopic index in CD.

An Expert Consensus to Standardize Assessment of Bowel Cleansing for Clinical Trials of Bowel Preparations for Crohn's Disease.

BACKGROUND: Despite regular need for colonoscopy in patients with Crohn's disease (CD), the efficacy and tolerability of bowel preparation (BP) agents is rarely assessed in this population. Assessing BP quality with existing scales may be challenging in CD due to presence of inflammation, bowel resection, and strictures. AIMS: To provide recommendations for assessing BP quality in clinical trials for CD using a modified Research and Development/University of California, Los Angeles appropriateness process. METHODS: Based on systematic reviews and a literature search, 110 statements relating to BP quality assessment in CD were developed. A panel of 15 gastroenterologists rated the statements as appropriate, uncertain, or inappropriate using a 9-point Likert scale. RESULTS: Panelists considered it appropriate that central readers, either alone or with local assessment, score BP quality in clinical trials. Central readers should be trained on scoring BP quality and local endoscopists on performing high-quality video recording. Both endoscope insertion and withdrawal phases should be reviewed to score BP quality in each colonic segment and segments should align with endoscopic disease activity indices. The Harefield Cleansing Scale and the Boston Bowel Preparation Scale were considered appropriate. The final score should be calculated as the average of all visualized segments. Both total and worst segment scores should also be assessed. CONCLUSIONS: We developed a framework for assessing BP quality in patients with CD based on expert feedback. This framework could support the development or refinement of BP quality scales and the integration of BP quality assessment in future CD studies.

Reliability and responsiveness of endoscopic disease activity assessment in eosinophilic esophagitis.

BACKGROUND AND AIMS: Endoscopic outcomes have become important measures of eosinophilic esophagitis (EoE) disease activity, including as an endpoint in randomized controlled trials (RCTs). We evaluated the operating properties of endoscopic measures for use in EoE RCTs. METHODS: Modified Research and Development/University of California Los Angeles appropriateness methods and a panel of 15 international EoE experts identified endoscopic items and definitions with face validity that were used in a 2-round voting process to define simplified (all items graded as absent or present) and expanded versions (additional grades for edema, furrows, and/or exudates) of the EoE Endoscopic Reference Score (EREFS). Inter- and intrarater reliability of these instruments (expressed as intraclass correlation coefficients [ICC]) were evaluated using paired endoscopy video assessments of 2 blinded central readers in patients before and after 8 weeks of proton pump inhibitors, swallowed topical corticosteroids, or dietary elimination. Responsiveness was measured using the standardized effect size (SES). RESULTS: The appropriateness of 41 statements relevant to EoE endoscopic activity (endoscopic items, item definitions and grading, and other considerations relevant for endoscopy) was considered. The original and expanded EREFS demonstrated moderate-to-substantial inter-rater reliability (ICCs of .472-.736 and .469-.763, respectively) and moderate-to-almost perfect intrarater reliability (ICCs of .580-.828 and .581-.828, respectively). Strictures were least reliably assessed (ICC, .072-.385). The original EREFS was highly responsive (SES, 1.126 [95% confidence interval {CI}, .757-1.534]), although both expanded versions of EREFS, scored based on worst affected area, were numerically most responsive to treatment (expanded furrows: SES, 1.229 [95% CI, .858-1.643]; all items expanded: SES, 1.252 [95% CI, .880-1.667]). The EREFS and its modifications were not more reliably scored by segment and also not more responsive when proximal and distal EREFSs were summed. CONCLUSIONS: EREFS and its modifications were reliable and responsive, and the original or expanded versions of the EREFS may be preferred in RCTs. Disease activity scored based on the worst affected area optimizes reliability and responsiveness.

An expert consensus to standardise clinical, endoscopic and histologic items and inclusion and outcome criteria for evaluation of pouchitis disease activity in clinical trials.

BACKGROUND: Pouchitis is a condition with large unmet medical needs and no approved therapies. Lack of validated instruments to measure disease activity and treatment response is a major barrier to drug development. AIM: To conduct a modified RAND/University of California Los Angeles appropriateness process to produce a standardised assessment of pouchitis disease activity in clinical trials. METHODS: A list of 164 items generated upon a systematic review and expert opinion were rated based on a 9-point scale (appropriate, uncertain and inappropriate), by a panel including 16 gastroenterologists, surgeons and histopathologists. RESULTS: Items rated as appropriate to evaluate in pouchitis clinical trials were: (a) clinical: stool frequency and faecal urgency; (b) endoscopic: primary assessment in the pouch body according to the percentage of affected area (<50%, 50%-75% and >75%), evaluation of the presence of ulcers/erosions according to size (erosions <5 mm, ulcers ≥5 mm to 2 cm and large ulcers >2 cm) and ulcerated area (<10%, 10%-30% and >30%); (c) histologic: two biopsies from each segment, from the ulcer's edge when present, or endoscopically normal areas, assessment of lamina propria chronic inflammation, epithelial and lamina propria neutrophils, epithelial damage, erosions and ulcers; and (d) clinical trial inclusion/outcome criteria: minimum histologic disease activity for inclusion, a primary endpoint based on stool frequency and assessment of clinical, endoscopic and histologic response and remission. The overall majority of items surveyed (100/164) were rated 'uncertain'. CONCLUSION: We conducted a RAND/UCLA appropriateness process to help inform measurement of pouchitis disease activity within clinical trials and foster the development of novel therapies.