Validation of the Mayo Dysphagia Questionnaire

Abstract

While multiple instruments characterize upper gastrointestinal symptoms, a validated instrument devoted to the measurement of a spectrum of esophageal dysphagia attributes is not available. Therefore, we constructed and validated the Mayo Dysphagia Questionnaire (MDQ). The 27 items of the MDQ underwent content validity, feasibility, concurrent validity, reproducibility, internal consistency, and construct validity testing. To assess content validity, five esophageal subspecialty gastroenterologists reviewed the items to ensure inclusion of pertinent domains. Feasibility testing was done with eight outpatients who refined problematic items. To assess concurrent validity, 70 patient responses on the MDQ were compared to responses gathered in a structured patient-physician interview. A separate group of 70 outpatients completed the MDQ twice to assess the reproducibility of each item. A total of 148 patients participated in the validation process (78 [53%] men; mean age 62). On average, the MDQ took 6 minutes to complete. A single item (odynophagia) tested poorly with a kappa value of <0.4. Otherwise, the majority of concurrent validity kappa values were in the good to excellent range with a mean of 0.63 (95% CI 0.22-0.89). The majority of reproducibility kappa values were also in the good to excellent range with a median kappa value of 0.76 (interquartile range: 0.67-0.81). Cronbach's alpha values were excellent in the range of 0.86-0.88. Spearman rank correlation coefficients to assess construct validity were also excellent in the range of 0.87-0.98. Thus, the MDQ is a concise instrument that demonstrates overall excellent concurrent validity, reproducibility, internal consistency, and construct validity for the features of esophageal dysphagia.