International validation of a health‐related quality of life questionnaire in patients with erosive gastro‐oesophageal reflux disease

Abstract

Factor analysis showed consistency of the dimensions and no reduction was necessary. Validation of GERDyzer indicated high internal consistency (Cronbach's alpha = 0.95) and test-retest reliability (intraclass correlation coefficient =0.91). Responsiveness of the total score expressed by nonparametric effect size was 1.38. Comparison of scores with other questionnaires resulted in logical correlation levels depending on the respected concepts measured. Conclusions GERDyzer proved to be highly valid, reproducible and responsive. It allows reliably assessing treatment-induced changes in HRQoL in erosive GERD.