Discussion
dysphagia, EoE
DYSPHAGIA, EOE
The EoE-IQ is a novel instrument for evaluating the impact of EoE in adults and adolescents, and this analysis of the EoE-IQ is, to our knowledge, the first psychometric evaluation of an EoE-specific HRQOL measure using data from a randomized phase 3 trial. While clinical trials in EoE appropriately focus on the symptom of dysphagia as a co-primary endpoint, given the impacts of EoE symptoms on broader aspects of patients’ daily lives and functioning, it is important to understand how new treatment options can alleviate these other impacts as well. Patient-reported outcome measures—such as the EoE-IQ—that are well-defined, reliable, valid, and responsive for use with both adolescents and adults in a clinical trial setting are needed to comprehensively capture patients’ experiences with treatment.These analyses support the EoE-IQ as a valid and reliable measure to assess the patient-reported impact of EoE among adult and adolescent patients, complementing evidence of the content validity of the measure. The psychometric results revealed that the EoE-IQ average score has adequate distributional properties, measurement structure, internal consistency, test–retest reliability, convergent and divergent construct validity, known-groups validity, and ability to detect change. Notably, the EoE-IQ was shown to correlate as expected with other EoE-specific patient-reported measures (i.e., PGIS, PGIC, EoE-SQ, and DSQ) and did so more closely than with clinical and endoscopic measures (i.e., EoE-EREFS and peak esophageal intraepithelial eosinophil counts). Patterns of change scores and large between-group effect sizes in comparisons between subgroups with and without improvement (as defined by PGIS and PGIC) demonstrated the ability of the EoE-IQ to detect change. In addition, when using a 1-point improvement on the PGIS as the primary anchor to explore thresholds for within-patient change, a 0.6-point reduction in the EoE-IQ average score is proposed as a clinically meaningful improvement on this measure.While existing measures are available to evaluate HRQOL in patients with EoE, these measures were developed for either an adult population or a pediatric population [This analysis is strengthened by the use of data from a phase 3 trial involving both adults and adolescents. Although the analysis sample of participants in the R668-EE-1774 trial was selected according to study eligibility criteria, participants in the trial were representative of the overall EoE patient population [In summary, the 11-item EoE-IQ focuses on concepts of importance to patients, is easy to administer, and is able to detect clinically meaningful change with treatment. Future validation studies may explore application of the EoE-IQ in contexts of use other than the clinical trial setting.