Background and Aims: The international E EsAI s tudy g roup
is currently d eveloping the first activity index ( EEsAI) specific
for E osinophilic Esophagitis (EoE). G oal: T o develop, e valuate
and validate the EEsAI.
Methods: T he development c omprises three p hases: 1.
Selection of c andidate items ( completed); 2. Evaluation of t he
activity index i n a first patient cohort (in progress, p atient
recruitment completed); and 3. Validation in a s econd EoE
patient cohort. F ocus group interviews with patients were used
in p hase 1 to g enerate patient r eported outcomes (PRO)
according to g uidelines o f regulatory authorities (FDA a nd
EMA), whereas the section of biologic items was developed by
Delphi rounds o f international E oE experts from E urope and
North America.
Results: T he EEsAI has a modular c omposition to a ssess the
following components o f EoE activity: p atient r eported
outcomes, e ndoscopic activity, histologic activity, laboratory
activity, a nd quality of l ife (QoL). Definitions for a ll aspects o f
endoscopic and histologic appearance were e stablished by
consensus r ounds a mong E oE experts. S ymptom a ssessment
tools were c reated that t ake into account d ifferent food
consistencies as w ell as f ood avoidance and specific
processing strategies. The EEsAI i s currently e valuated in a
cohort of a dult EoE patients since M arch 2 011 (patient
recruitment completed).
Conclusions: The EEsAI standardizes outcome assessment in
EoE t rials. T he collaboration with i nternational E oE e xperts a s
well as f ollowing o f the guidelines f rom regulatory authorities
will lead to its wide applicability.