Development of the Northwestern Esophageal Quality of Life Scale: A Hybrid Measure for Use Across Esophageal Conditions

Abstract

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.

Systematic review: health‐related quality of life in children and adults with eosinophilic oesophagitis—instruments for measurement and determinant factors

“…16 We identified three different HRQoL-specific measures used for patients with EoE. 11,12,18,32 We assessed the internal consistency, reliability, measurement error, content validity, factor analysis, construct validity, responsiveness, and ceiling and flooring effects, 15 depending on the information obtained from the literature. which may be influenced by the biological activity of the disease as determined by the severity of endoscopic features, 28 including the presence of oesophageal strictures at diagnosis.…”

“…We identified three different HRQoL‐specific measures used for patients with EoE . We assessed the internal consistency, reliability, measurement error, content validity, factor analysis, construct validity, responsiveness, and ceiling and flooring effects, depending on the information obtained from the literature.…”

“…Of the remaining 58 documents retrieved for complete evaluation, 24 were excluded for the following reasons: duplicated abstracts or abstracts previous to full papers (12), lack of information regarding QoL (6) or QoL not structurally assessed (4), subsets of patients included in later papers (1) and no information related with EoE (1). In the end, 34 studies (comprising of 16 full papers 11,12,18,19,21,22,[24][25][26][27][28][29][30][31] and 18 abstracts [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] (one of them later published in full 50 ) were included in our systematic review ( Figure 1).…”

“…Regarding the aims of the retrieved studies, the references retrieved included five papers on specific questionnaire developments, 11,12,18,21,22 1 abstract on item refinement 32 and 1 trans-cultural adaptation and validation of a questionnaire. 26 In addition, 14 studies assessed HRQoL by generic instruments, 19,24,25,27,29,[33][34][35][36]39,49 while 11 documents employed diseasespecific scales.…”

Evaluating the reliability and construct validity of the Eckardt symptom score as a measure of achalasia severity

“…Based on FDA guidelines, the ESS should undergo further evaluation via cognitive interviews with individual achalasia patients to understand their interpretation and answers to each item, a process undertaken for more recently developed measures such as the Northwestern Esophageal Quality of Life Scale (NEQOL) 24 and the Eosinophilic Esophagitis Quality of Life Scale for Adults (EoE-QOL-A) 25 . Additional focus groups may be needed to more comprehensively capture the clinical presentation of chest pain and weight loss symptoms in achalasia patients, thereby strengthening the construct validity of the ESS.…”