Development and assessment of a modified Pediatric Crohn Disease Activity Index

Identifying predictors of clinical outcomes using the projection-predictive feature selection-a proof of concept on the example of Crohn's disease

Objectives

Several clinical disease activity indices (DAIs) have been developed to noninvasively assess mucosal healing in pediatric Crohn's disease (CD). However, their clinical application can be complex. Therefore, we present a new way to identify the most informative biomarkers for mucosal inflammation from current markers in use and, based on this, how to obtain an easy-to-use DAI for clinical practice. A further aim of our proof-of-concept study is to demonstrate how the performance of such a new DAI can be compared to that of existing DAIs.

Methods

The data of two independent study cohorts, with 167 visits from 109 children and adolescents with CD, were evaluated retrospectively. A variable selection based on a Bayesian ordinal regression model was applied to select clinical or standard laboratory parameters as predictors, using an endoscopic outcome. The predictive performance of the resulting model was compared to that of existing pediatric DAIs.

Results

With our proof-of-concept dataset, the resulting model included C-reactive protein (CRP) and fecal calprotectin (FC) as predictors. In general, our model performed better than the existing DAIs. To show how our Bayesian approach can be applied in practice, we developed a web application for predicting disease activity for a new CD patient or visit.

Conclusions

Our work serves as a proof-of-concept, showing that the statistical methods used here can identify biomarkers relevant for the prediction of a clinical outcome. In our case, a small number of biomarkers is sufficient, which, together with the web interface, facilitates the clinical application. However, the retrospective nature of our study, the rather small amount of data, and the lack of an external validation cohort do not allow us to consider our results as the establishment of a novel DAI for pediatric CD. This needs to be done with the help of a prospective study with more data and an external validation cohort in the future.

Fecal Calprotectin, Chitinase 3-Like-1, S100A12 and Osteoprotegerin as Markers of Disease Activity in Children with Crohn’s Disease

Fecal calprotectin (FC), chitinase 3-like-1 protein (CHI3L1), S100A12 and osteoprotegerin (OPG) are biomarkers of intestinal inflammation. This cross-sectional study aimed to evaluate these biomarkers in a cohort of children with Crohn’s disease (CD) and compare them with other measures of disease activity. Stool samples from children with CD were used to measure FC, CHI3L1, S100A12 and OPG by enzyme-linked immunosorbent assay. Serum inflammatory markers were measured and pediatric CD disease activity index (PCDAI) scores calculated. The simple endoscopic score for CD (SES-CD) was reported for a subgroup who underwent ileocolonoscopy corresponding with the stool samples. Sixty-five children were recruited. Children in clinical remission had lower FC and CHI3L1 levels than those with active disease (FC: 277 vs. 1648 µg/g, p = 0.012; CHI3L1: 23 vs. 227 ng/g, p = 0.013). FC levels differed between patients with clinically active or inactive isolated ileal CD. Although FC and CHI3L1 levels correlated strongly (r = 0.83), none of the fecal markers correlated well with serum markers. Only FC and OPG correlated with SES-CD scores (r = 0.57 and r = 0.48, respectively). In conclusion, FC correlated with both endoscopic and clinical disease activity and was the only biomarker that differentiated between active and inactive ileal CD. CHI3L1 also predicted clinical disease activity and correlated highly with FC. Further investigation of the role of CHI3L1 is required.

Cytokine profile in serum and gingival crevicular fluid of children with inflammatory bowel disease: A case-control study

BACKGROUND

To evaluate the cytokine profile in gingival crevicular fluid (GCF) and serum of pediatric inflammatory bowel disease (IBD) patients and determine the cluster patterns of cytokines.

METHODS

Fifty IBD patients and 21 systemically healthy children were enrolled in the study. The GCF samples were collected from the participants during periodontal examination and periodontal indices were recorded. Based on activity indexes and response to conventional treatment, patients with IBD were further categorized into subgroups as: remission, active disease, and treatment-resistant. Serum samples were obtained from IBD patients to determine serum levels of cytokines. The levels of pro- (interleukin (IL)-1β, IL-12, IL-21, IL-22, IL-23, IL-17A, IL-17F) and anti-inflammatory (IL-4, IL-10) cytokines in serum and GCF were measured using Enzyme-linked Immunosorbent Assay (ELISA) kits.

RESULTS

Among 50 IBD patients, 58% were in remission, 20% had active disease, and 22% were defined as treatment-resistant. The severity of gingival inflammation measured by the criteria of Löe had increasing trends in IBD patients with active disease and treatment resistance. GCF IL-1β level was lower and GCF IL-4 and GCF IL-23 levels were higher in IBD patients compared to healthy controls. In the active disease group, more cytokine clusters occurred compared to the control group and other IBD subgroups, as explained by increased cytokine-cytokine interactions.

CONCLUSIONS

Considering the increased complexity of cytokine interactions and the increased severity of gingival inflammation in patients with active disease, it can be concluded that disease activity might have an impact on gingival inflammation in pediatric patients with IBD.

Vulvar Crohn's disease in an adolescent diagnosed after unsuccessful surgical treatment

BACKGROUND

This case report presents a case of Vulvar Crohn's disease (VCD) in an adolescent, that is an uncommon manifestation of Crohn's disease (CD) without gastrointestinal symptoms. Before treating CD itself with proper medication, vulvar abscess continued to recur without improvement.

CASE PRESENTATION

We report the case of an 18-year-old woman with VCD. After treatment with azathioprine 50 mg daily and mesalazine 1 g three times daily, vulvar lesions resolved after 6 weeks. We collected electronic medical data on patient characteristics, and evaluated findings of physical examinations, pelvic MRI, and biopsy specimen obtained from gastroduodenoscopy/colonoscopy.

CONCLUSIONS

VCD is a rare manifestation of CD that may be misdiagnosed in the absence of gastrointestinal symptoms leading to delayed treatment. If a patient has an unexplained vulvar inflammatory lesion and with repeated failed surgical treatment, gynecologists should consider the possibility of a VCD.

Assessing disease activity using the pediatric Crohn’s disease activity index: Can we use subjective or objective parameters alone?

BACKGROUND

The pediatric Crohn’s disease activity index (PCDAI) is used as a standard tool to assess disease activity in clinical trials for pediatric Crohn’s disease.

AIM

To examine which items on the PCDAI drive assessment of disease activity, and how subgroups of subjective and objective items reflect change in disease state over time.

METHODS

Selective raw data from three prospectively collected datasets were combined, including 703 children with full PCDAI data at baseline, at 3-mo (Q1, n = 670), and 1-year (Q4, n = 474). Change in individual PCDAI scores from baseline to Q1 and to Q4 were examined using the non-weighted PCDAI.

RESULTS

Abdominal pain, well-being, weight, and stooling had the highest change scores over time. Objective indicators including albumin, abdominal exam, and height velocity followed. Change scores for well-being and abdominal exam did not explain significant variance at Q1 but were significant predictors at Q4 (P < 0.001 and P < 0.05). Subjective and objective subgroups of items predicted less variance (18% and 22%) on total PCDAI scores at Q1 and Q4 compared to the full PCDAI, or a composite scale (both 32%) containing significant predictors.

CONCLUSION

Although subjective items on the PCDAI change the most over time, the full PCDAI or a smaller composite of items including a combination of subjective and objective components classifies disease activity better than a subgroup of either subjective or objective items alone. Reliance on subjective or objective items as stand-alone proxies for disease activity measurement could result in misclassification of disease state.

Infliximab treatment of glycogenosis Ib with Crohn's-like enterocolitis: A case report

BACKGROUND

Glycogen storage disease type Ib (GSD-Ib) is a glycogen metabolism disorder that leads to the manifestations of inflammatory bowel disease (IBD), especially Crohn’s disease (CD)-like colitis. Although biological agents are effective for treating CD, their application in the treatment of GSD-Ib with CD-like colitis has been rarely reported.

CASE SUMMARY

A 13-year-old Han male was diagnosed with GSD-Ib with CD. The patient was treated with granulocyte colony-stimulating factor. When he had symptoms of CD-like colitis, he was continuously pumped with enteral nutrition and administered oral mesalazine for 2 wk; however, the symptoms did not improve significantly. Hence, infliximab (IFX) was administered. Hitherto, the patient has been followed up for 1 year, and no clinical manifestations have been observed. After 6 mo of treatment (fifth IFX treatment), the disease activity index and all inflammatory indexes decreased, and a review of the colonoscopy data showed that the ulcers appeared smooth.

CONCLUSION

In this study, the patient was successfully treated with IFX. In cases of GSD-Ib, IBD should be highly considered.

An Overview of Tools to Score Severity in Pediatric Inflammatory Bowel Disease

Background and Aims: The management of IBD entails the use of various treatments (nutrition, medications, and surgery) in order to induce and maintain remission. The assessment of IBD disease activity is based on a combination of symptoms, clinical findings, imaging, and endoscopic procedures. As in any disease, reliable assessment of disease activity or severity is required in order to plan relevant follow-up, decide on appropriate investigations, determine the best treatment option and subsequently assess response to treatment. It is important for proper documentation, follow-up, assessment of response to treatment and communication, especially in patients with IBD, to talk the same language by using validated and widely used scores for disease activity, endoscopic and radiologic activity, and patient reported outcomes both for clinical practice and research. This review aims to highlight key tools available for the assessment of disease activity or severity in individuals (especially children) with IBD. Methods: A literature search was performed using MEDLINE, Pubmed, and the Cochrane Library with the last search date of August 2020. Tools evaluating disease severity across various aspects (clinical, endoscopic, and radiological) were identified and discussed. Those tools validated and specific for children with IBD were included were available. Results: Over time a number of scoring systems have been developed to quantify clinical, endoscopic and imaging assessments in individuals with IBD. While some are exclusively for children or adults, others appear to have relevance to all age groups. In addition, some tools developed in adult populations are utilized in children, but have not expressly been validated in this age group. Conclusions: Although some available scoring tools are appropriate for children with IBD, others require consideration. The development and use of pediatric-specific tools is relevant and appropriate to optimal care of children and adolescents with IBD.

IBD phenotype at diagnosis, and early disease-course in pediatric patients in Croatia: data from the Croatian national registry

BACKGROUND

Pediatric inflammatory bowel disease (IBD) presents with extensive phenotype. The aim of this study was to determine the phenotype of pediatric IBD patients in Croatia at diagnosis and follow-up.

METHODS

Children were prospectively recruited into Croatian IBD national registry. Data on diagnostic evaluation, therapy and 1-year follow-up were collected.

RESULTS

A total of 51 newly diagnosed patients were recruited (19 Crohn's disease (CD), 28 ulcerative colitis (UC) and 4 IBD-unclassified (IBD-U)). Most common location in CD was ileocolonic disease (52.6%), and pancolitis in UC (53.6%). The recommended complete diagnostic algorithm was performed only in 29.4% of patients. First-line therapy used in CD was exclusive enteral nutrition for remission induction (84.2%) and azathioprine for maintenance (73.7%). In patients with UC, aminosalicylates were the most common drug used (89.3%). By the end of the first year 41.2% of CD and 53.9% of UC patients had one or more relapses and required treatment escalation.

CONCLUSION

Our data confirm extensive intestinal involvement in pediatric IBD and relatively high relapse rate during the first year of follow-up. More effort should be invested on the national level to implement more stringent adherence to the current European guidelines.

IMPACT

The key message of our article is that pediatric IBD in Croatia shows extensive intestinal involvement with high relapse rates in first year of follow-up. It is the first cohort study reporting on the phenotype of pediatric IBD in Croatia, but also investigates adherence to diagnostic and therapeutic European guidelines which is not commonly reported. The study is national based, thus having the greatest impact on Croatian health care,stressing out that more effort should be invested on the national level to implement more stringent adherence to the current European guidelines.

Incidence and Geographical Variability of Pediatric Inflammatory Bowel Disease in Croatia: Data From the Croatian National Registry for Children With Inflammatory Bowel Disease

The aim of this study was to determine the annual incidence and geographic distribution of pediatric inflammatory bowel disease (IBD) in Croatia. This is a prospective, cohort, multicenter observational study based on the data obtained from the Croatian national registry for children with IBD. Children and adolescents younger than 18 years diagnosed with IBD, in time period between June 1, 2016, and May 31, 2017, were recruited. In total, 51 new cases were identified; 19 Crohn's disease, 28 ulcerative colitis, and 8 IBD-unclassified. Male preponderance of all 3 types of the disease was noticed. The median age at diagnosis was 14.8 years. The calculated annual incidence of pediatric IBD per 100 000 persons per year was 7.05 (2.63 for Crohn's disease, 3.87 for ulcerative colitis, and 0.55 for IBD-unclassified). A north to south gradient was observed with almost 2 times higher incidence in the northern region of the country.

Fecal Amino Acid Profiles Exceed Accuracy of Serum Amino Acids in Diagnosing Pediatric Inflammatory Bowel Disease

In this prospective intention-to-diagnose pilot study, we aimed to assess accuracy of serum and fecal amino-acids to discriminate de novo pediatric inflammatory bowel disease (IBD) and non-IBD children. Patients with suspected IBD were allocated the IBD (n = 11) or non-IBD group (n = 8) following laboratory testing or endoscopy according to the revised Porto-criteria. Fecal calprotectin levels were obtained, an additional blood and fecal sample were collected. Fecal and serum amino-acid profiles were analyzed using high performance-liquid chromatography. Nine fecal amino-acids (alanine [area under the curve 0.94], citrulline [0.94], glutamine [0.89], leucine [0.98], lysine [0.89], phenylalanine [0.99], serine [0.91], tyrosine [0.96], and valine [0.95]) differed significantly between IBD and non-IBD. In serum, no significant differences were observed. This study underlines the potential of fecal amino-acids as novel, adjuvant noninvasive, and low-cost biomarkers in the diagnostic work-up of pediatric IBD detection.

Three-year outcomes of childhood inflammatory bowel disease in New Zealand: A population-based cohort study

Background and Aim

High rates of inflammatory bowel disease (IBD) have been documented in New Zealand (NZ) children. The objectives of this study were to describe the outcomes and disease course of childhood IBD in the first 3 years following diagnosis.

Methods

All children diagnosed with IBD in 2015 in NZ were included. Clinical data obtained during routine care for 3 years following diagnosis were analyzed. Growth parameters, disease activity scores, and blood parameters were compared at diagnosis and follow up.

Results

Three‐year outcome data were available for 48 of 51 children. At follow up, median age was 15.1 years, and 34 had Crohn's disease (CD), 11 had ulcerative colitis (UC), and three had IBD‐unclassified (IBDU). Although disease progression including development of perianal disease occurred in 13 (38%) of 34 children with CD, the majority (n = 30) had inflammatory disease at follow up. Disease extension occurred in 25% (2/8) of children initially diagnosed with UC. Of all IBD patients, the mean body mass index z‐score increased from −0.40 to +0.10 (P = 0.01). Disease activity scores reduced from diagnosis to follow up in both CD (mean pediatric Crohn's disease activity index 35–6, P < 0.001) and UC (mean pediatric ulcerative colitis activity index 44–6, P < 0.001). Overall, 56% of children received steroids, 44% of children with CD received biologic therapy, and four children with CD or UC had intestinal surgery.

Conclusions

Most children with IBD were in remission with improved growth 3 years after diagnosis. Biologic therapies were commonly prescribed. This is the first NZ study assessing disease course in pediatric IBD. Ongoing follow up will continue to inform outcomes.

Fecal Markers of Inflammation and Disease Activity in Pediatric Crohn Disease: Results from the ImageKids Study

BACKGROUND

Noninvasive and accurate methods to monitor inflammatory bowel disease are required. As a planned ancillary study of the prospective ImageKids cohort, we aimed to assess the performance of fecal calprotectin (FC) with comparison to 3 fecal inflammatory markers; S100A12 (FA12), tumor pyruvate kinase isoenzyme type M2 (FM2PK) and fecal osteoprotegerin (FOPG) as indicators of a number of disease characteristics.

METHODS

The ImageKids study was a multicenter study designed to develop 2 magnetic resonance enterography-based measures for children with Crohn disease (6-18 years old). All patients underwent magnetic resonance enterography, a complete ileocolonoscopic evaluation and provided a fecal sample. Fecal samples were assay for FC, FA12, FM2PK, and FOPG by ELISA.

RESULTS

One-hundred fifty-six children provided 190 fecal samples. Median (interquartile range) for fecal makers were FC, 602 (181-1185) μg/g; FA12, 21 (3-109) μg/g; FM2PK, 16 (2-20) U/mL; and FOPG, 125 (125-312) μg/g. All markers correlated with simple endoscopic severity index for Crohn disease and with other constructs of disease activity, but FC had the highest overall correlations. FA12, however, predicted mucosal healing with significantly higher specificity (87% vs 70%, P = 0.004) and equivalent sensitivity (91% vs 90%) compared to FC.

CONCLUSION

This study has confirmed that FC is useful, and overall best, marker to monitor mucosal inflammation in inflammatory bowel disease. FA12, however, appears to be a more suitable maker for prediction of mucosal healing in children.

A Symptom Self-report Tool for Children With Inflammatory Bowel Disease (IBDnow)

OBJECTIVES

Clinical symptom evaluation for children with inflammatory bowel disease (IBD) is typically done using composite tools: the Pediatric Crohn's Disease Activity Index (PCDAI) and Pediatric Ulcerative Colitis Activity Index (PUCAI). Both rely on clinician interpretation of child or parent symptom recall. No universal self-report tool has yet been developed for children with IBD to assess and report their symptoms. The research objective was to develop a self-report tool that produced information congruent with that obtained by clinicians using the PUCAI or PCDAI.

METHODS

A children's symptom self-report tool (IBDnow) was developed with picture and text Likert symptom scales. The clinician and child completed their reports during the same outpatient consultation. Agreement levels were calculated at the individual level (identical child and clinician answers), category level (symptom severity), and aggregate level (cohort scores). Internal consistency was measured with Cronbach alpha.

RESULTS

One hundred children from Christchurch (New Zealand) (n = 65), and Sydney (Australia) (n = 35) completed the study (Crohn's Disease (CD):88, ulcerative colitis (UC):12), mean age 13.9 years (±3.6). Mean individual agreement was 0.76 (±0.19). Category severity had very good or good inter-rater reliability for 5 of the 7 symptom scales and overall severity agreement of 76%. Aggregate mean scores were significantly different between clinicians (14.9, ±18.8), and participants (21.6, ±19.4), (P <0.005, confidence interval -9.0, -4.4), but 60 pairs had scores within a 10% margin. Cronbach alpha was 0.74.

CONCLUSIONS

This self-report tool had good proportionate agreement between raters, and good crude agreement for symptom categories. Assigning PUCAI or PCDAI scores caused inter-rater discrepancies to be misleadingly magnified. Pediatric gastroenterologists may consider utilizing IBDnow to elicit symptom self-reports from children with IBD to enable them to communicate meaningful information on their ongoing symptom burden. This would be a positive step in helping children feel included in clinical encounters and promoting self-management, at the same time producing valid, subjective symptom recall.

Novel Biomarkers and the Future Potential of Biomarkers in Inflammatory Bowel Disease

There is increasing importance placed upon noninvasive assessment of gut inflammation. These tools are likely to be the key in differentiating intestinal inflammatory disease from functional disorders and in monitoring the response to intervention in individuals with known inflammatory conditions. Although various noninvasive markers are currently available, they have limitations and do not provide ideal utility. This review focuses on emerging markers of gut inflammation, highlighting the potential of specific markers.

Pediatric Crohn Disease Clinical Outcome Assessments and Biomarkers: Current State and Path Forward for Global Collaboration

OBJECTIVE

There is a pressing need for drug development in pediatric Crohn disease (CD). Our aim was to provide strategic approaches toward harmonization of current thinking about clinical outcome assessments (COAs) and biomarkers to facilitate drug development in pediatric CD.

METHODS

Scientists from the United States Food and Drug Administration, European Medicines Agency, Health Canada, and the Pharmaceuticals and Medical Devices Agency of Japan had monthly teleconferences from January 2014 through May 2015. A literature review was conducted to assess the measurement properties of all existing COA tools and to evaluate the current landscape of biomarkers used in pediatric CD. Based on the findings of literature review, we reached the consensus on the strategic approaches for evaluating outcomes in pediatric CD trials.

RESULTS

The pediatric Crohn's Disease Activity Index, Crohn's Disease Activity Index, and Harvey-Bradshaw's index were used in pediatric CD clinical studies. But they lack adequate measurement properties (validity, reliability, and ability to detect change of the treatment) that are required to support approval of products intended to treat pediatric CD. Biomarkers (ie, fecal lactoferrin, osteoprotegerin, and calprotectin) have shown some promise for their potential as noninvasive surrogate endpoints in CD.

CONCLUSIONS

Lack of well-defined and reliable COAs presents a hurdle for global drug development in pediatric CD. It is essential to develop well-defined and reliable COAs that can measure meaningful clinical benefit for patients in terms of how they feel, function, and survive. Development of noninvasive biomarkers as reliable surrogate endpoints needs to be further explored.

Well-defined and reliable clinical outcome assessments for pediatric Crohn disease: a critical need for drug development

OBJECTIVES

The aim of the present study was to identify areas for further development of clinical outcome assessment (COA) in pediatric Crohn disease (CD).

METHODS

The study analyzed the measurement properties of all existing COA tools for pediatric CD in literature and published registration trials of approved drugs for pediatric CD based on criteria described in Food and Drug Administration guidance for patient-reported outcome (PRO) development.

RESULTS

The Pediatric Crohn's Disease Activity Index (PCDAI) and its derivatives (abbreviated, short, modified, and weighted PCDAIs) were reviewed. The Crohn's Disease Activity Index (CDAI) and Harvey-Bradshaw index (HBI), designed for adult patients, have been adapted for use in a few pediatric CD studies. The use of PCDAI as an endpoint in Remicade and Humira trials led to the Food and Drug Administration-approved indication in pediatric CD. Common issues in measurement properties of COA tools included the absence of direct patient or caregivers' input to generate the items measuring signs and symptoms; absence of evidence demonstrating correlation with clinically relevant inflammation observed with endoscopic measures; lack of standardization in measurement, age-appropriate interviewer script, and response rating criteria for the physician interviewer.

CONCLUSIONS

Available evidence indicates that CDAI, HBI, and 5 versions of the PCDAI lack adequate measurement properties for use as a primary endpoint for phase 3 trials intended to support approval of products intended to treat pediatric CD. In order to facilitate pediatric drug development, a well-defined, reliable, sensitive, and globally recognized PRO that measures signs and symptoms in children with CD and that can be used in conjunction with endoscopy-based endpoints and/or biomarkers is sorely needed.

Chronic pain in inflammatory bowel disease: characteristics and associations of a hospital-based cohort

BACKGROUND

Chronic pain (CP) is a common symptom in patients with inflammatory bowel disease. This study aimed to examine its prevalence, severity, clinical associations, and impact on psychological well-being and to identify patient factors that independently predict the presence of severe/disabling pain.

METHODS

One hundred and twenty consecutive patients with inflammatory bowel disease attending a hospital-based clinic provided information through questionnaires on quality of life, mood disturbance, and functional gut symptoms. Those who had CP (pain occurring every day for 3 months within the past 6 months) provided additional information on the pain's intensity and associated disability and management and coping strategies.

RESULTS

Forty-six patients (38%) had CP, most commonly in the abdomen (91%), and they had higher disease activity, reduced quality of life, and more depression and anxiety and took more paracetamol and opiates than those without. These indices were worse in the subgroup of 23 with moderate-severe pain/disability. Criteria for irritable bowel syndrome were met in 70% of those with pain irrespective of its severity. Multivariate analysis identified 4 independent associations with moderate-severe pain/disability: active disease (odds ratio, 49 [95% confidence intervals, 1.6-1455]), catastrophizing tendency (35 [3-228]), medication belief score (0.05 [0.005-0.55], and depression score (1.80 [1.02-3.17]).

CONCLUSIONS

CP has major effects on quality of life and functional and social outcomes. Active disease and maladaptive coping strategies and negative attitudes and beliefs toward symptoms are independently associated with more severe pain. Management strategies should move the focus away from analgesic dependence toward psychosocial intervention and nonpharmacologic therapy.

Mathematical weighting of the pediatric Crohn's disease activity index (PCDAI) and comparison with its other short versions

BACKGROUND

The Pediatric Crohn's Disease Activity Index (PCDAI) has become the standard outcome measure in pediatric Crohn's disease (CD) clinical research. Other versions have been proposed but without systematic evaluation. The aim was to assess validity and responsiveness of the abbreviated PCDAI (abbrPCDAI), short PCDAI (shPCDAI), and modified PCDAI (modPCDAI) as measures of disease activity and to compare these with a mathematically weighted version developed here (wPCDAI).

METHODS

The raw data from four prospectively collected datasets were used, totaling 437 children with CD (including two clinical trials). Discriminant validity utilized physician global assessment of disease activity (PGA), and construct validity the correlation with PGA and laboratory results. Feasibility and face validity were ascertained by a survey of 33 experts in pediatric CD.

RESULTS

The wPCDAI had better performance than the PCDAI in construct validity and responsiveness and it discriminated better between the disease activity categories (area under the receiver operator characteristic [ROC] 0.97; 95% confidence interval [CI]: 0.95-0.99). In comparison to the original PCDAI, the noninvasive versions (abbrPCDAI and shPCDAI) had lower face, construct, and discriminant validity but were judged to be significantly more feasible. The modPCDAI performed well in the construct validation but was consistently inferior in all other parameters. Cutoffs that correspond to remission, response, and gradations of disease activity were determined for each index.

CONCLUSIONS

The newly weighted wPCDAI performed better than the original PCDAI and is more feasible. The noninvasive versions (shPCDAI and abbrPCDAI) are inferior to the full PCDAI, but when needed in retrospective studies either may be equally used.