Development and Content Validity of an Observer-Reported Outcome (ObsRO) Diary for Use Among Caregivers of Children with Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) causes reflux-like symptoms and feeding problems in children, often differing from adult symptom presentation. Symptoms are best reported by patients themselves. However, for young children who are unable to self-report, an observer-reported outcomes (ObsROs) diary is vital for accurately measuring treatment benefit. This study investigated the content validity of an ObsRO diary being developed for use among caregivers of children (aged 2-10 years) with EoE. Two rounds of interviews were conducted. Round one elicited concepts related to EoE (observable behaviors and verbalizations) and assessed the completeness, relevance and comprehensibility of the ObsRO diary. Round two assessed the usability of the diary on an electronic device. Overall, 25 caregivers were enrolled. The mean (standard deviation) age of the children with EoE was 7.1 (2.4) years. Concept saturation, the point where no new concepts emerge, was achieved after the 12th interview with 22 concepts. The most commonly reported were stomach pain (n=21, 84%), avoiding/refusing food (n=15, 60%) and difficulty swallowing (n=13, 52%). All respondents confirmed that the ObsRO questions were relevant for their children and easy to understand. Caregivers (92%) reported that the electronic format was acceptable and easy to complete. The development of ObsROs is essential to ensure that patient experience is included in treatment assessments. This study supports the content validity of the EoE ObsRO caregiver diary. Caregivers observed concepts consistent with the heterogeneity of signs/symptoms of EoE reported in children. Further development of the ObsRO is required to determine its psychometric properties, scoring and meaningful change.