Project

eosinophilic esophagitis; activity index; patient reported outcomes; clinical trials; children; adolescents; adults

Lead
Lay summary
Die eosinophile Speiseröhren-Entzündung (medizinisch "eosinophile Oesophagitis") wurde erstmals 1993 als eigenständige Erkrankung beschrieben. Es handelt sich um eine allergie-artige Entzündung der Speiseröhre (diese stellt die Verbindung her zwischen Mundhöhle und Magen), gekennzeichnet durch eine Ansammlung von eosinophilen Entzündungszellen sowie Schluckbeschwerden oder Brustschmerzen. Im schlimmsten Falle bleibt die Nahrung in der Speiseröhre stecken und erfordert die notfallmässige Entfernung mittels Spiegelung. Unsere Arbeitsgruppe entwickelt ein Instrument um die Entzündungs-Aktivität der Eosinophilen Oesophagitis zu messen (sogenannter Aktivitäts-Index). Dieser Index hat zum Zweck objektive Kriterien für die Erfassung der Entzündungsaktivität zu definieren damit Resultate von verschiedenen Therapie-Studien miteinander verglichen werden können. Wir messen die Aktivität mittels Fragebogen auf den folgenden Ebenen: Beschwerden der Patienten, Aktivität in der Speiseröhrenspiegelung, Aktivität im Gewebe, Entzündung im Blut. Das Projekt hat 3 Phasen: 1. Erstellung der Fragebogen (abgeschlossen), 2. Patienten-Einschluss für Evaluation des Index (aktiv), 3. Patienten-Einschluss für Validierung des Index (nocht nicht begonnen). Das Projekt dauert bis 2014.

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Last update: 21.02.2013

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Background: Eosinophilic Esophagitis (EoE) is rapidly emerging as a distinctive chronic disorder in pediatric and adult gastroenterology. There is an urgent need for a validated activity index assessing symptoms and the biologic activity of the disease as an objective outcome measure for use in clinical trials, observational studies, and daily clinical practice. Objectives: We will develop and validate a multi-item instrument that can be used to reliably assess the disease activity in adult (ad-EEsAI) and pediatric (ped-EEsAI) EoE patients. Methods: The proposed project involves three distinct phases. While phase 1 is close to being finalized, phases 2 and 3 await completion and are part of this grant application: Phase 1: Selection of candidate items for the index. Item generation (symptoms, biologic markers such as endoscopic findings, histologic and laboratory measures), item reduction and instrument formatting have been achieved through a Delphi process within an international expert group. The goal of this phase was to reach a consensus on relevant items. Phase 2: Derivation of the activity index. In this phase, the item list generated during phase 1 will be evaluated prospectively in a cohort of patients (cohort A) in order to remove unnecessary items and to assess the relative contribution of the remaining items to the overall activity index. Phase 3: Validation of the derived activity index. The methodology of the activity index calculation developed in phase 2 will be validated in a second independent cohort (cohort B). Test-retest reliability and responsiveness of the score will be assessed using longitudinal data from the same patients. Study Population: Two prospective cohorts of adult and pediatric EoE patients will be recruited by collaborating centers in Switzerland, USA and Canada. Cohort A (phase 2) includes 100 adult and 100 pediatric patients, while cohort B (phase 3) includes 200 adult and 200 pediatric patients.Measurements: Physicians will use standardized questionnaires to record symptoms, biologic measures (endoscopic, histologic, and laboratory findings), and treatments of individual patients, and will also be required to provide an overall Physician’s Global Assessment (PGA) of the disease activity.Statistical Analyses: In Phase 2, data will be subjected to a linear regression analysis with the PGA as the primary outcome and variables reflecting the EEsAI items as explanatory variables. In Phase 3, regression coefficients from cohort A will be used to predict the PGA in patients from cohort B, which will then be compared to the recorded PGA provided by the physician. Agreement between predicted and recorded PGA will be analyzed. Test-retest variability and responsiveness to changes in PGA will be assessed using longitudinal data from cohort B. Interobserver variability will be evaluated by comparing 2 independent EEsAI assessments by 2 physicians. Sample size calculations have been performed for Phases 2 and 3. Output and significance: There is a consensus among leading EoE experts that a validated, standardized, and feasible instrument for the assessment of EoE activity is urgently needed in order to conduct prospective randomized clinical trials and natural history studies, as well as for monitoring patients in clinical practice. Therefore, this project represents the unique opportunity to standardize the assessment of EoE activity. The close collaboration with many internationally-recognized EoE centers and the carefully-planned methodology of this study will result in the generation of a widely-accepted disease activity index. Furthermore, recruitment of such large cohorts of patients will allow for a variety of nested projects with particular emphasis on translational research questions relevant to the field of EoE.