OBJECTIVES
Measures of health-related quality of life (HRQOL) in chronic esophageal conditions such as gastroesophageal reflux disease, eosinophilic esophagitis, and achalasia are widely used to measure this important patient-reported outcome. We seek to leverage these existing measures to create a hybrid measure of esophageal illness HRQOL (the Northwestern Esophageal Quality of Life—NEQOL), allowing for broad use across diseases while maintaining sensitivity to nuances of a specific condition.
METHODS
A three-step, mixed-methods process per FDA guidelines for patient-reported outcome (PRO) development was followed: review and consolidation of existing HRQOL measure items into a single questionnaire, reliability and validity analyses (principle components factor analysis, Cronbach alpha, Guttman split-half, inter-item correlation, test–retest correlation, and Pearson’s correlation with related constructs) based on responses from a representative sample of esophageal illness patients, and individual structured cognitive interviews with patients for item refinement and reduction.
RESULTS
An initial 30-item measure was created. Two-hundred twelve patients completed the reliability and validity portion of the study, and 15 completed cognitive interviews. Factor analysis and item-reduction resulted in 11 items being removed from the NEQOL prior to patient interviews. Construct validity was supported by moderate and significant correlations with psychological distress and general HRQOL. Test–retest reliability was excellent. Following patient interviews, an additional 5 items were removed because of floor effects or participant feedback yielding a 14-item, single scale measure of HRQOL.
CONCLUSIONS
Although more research is warranted, the NEQOL is a reliable and a valid hybrid measure of disease-specific HRQOL across several chronic esophageal conditions.