Objectives: Endoscopy-negative gastroesophageal reflux disease (GERD) lacks objective markers of disease severity. Evaluation of therapies for GERD must therefore rely on subjective measures, including patient self-report questionnaires, to measure the clinical effectiveness of therapeutic interventions. We aimed to evaluate the previously validated Gastrointestinal Symptoms Rating Scale (GSRS) and the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaires for reliability and responsiveness to change over time.
Methods: Patients (n = 1143) with heartburn, but no esophagitis included in a randomized clinical trial assessing the effectiveness of active treatment with proton pump inhibitors over 4 wk were evaluated.
Results: The test-retest reliability of both questionnaires over time was good to excellent (GSRS 0.53-0.69; QOLRAD 0.65-0.76), as was the responsiveness estimated by standardized response means (GSRS reflux dimension, -1.43; QOLRAD 0.81-1.43) and effect sizes (GRSR reflux dimension, -1.74; QOLRAD 0.82-1.56). The relationship between improvement in the GSRS reflux dimension score and the amount of clinical benefit as estimated by the patients themselves (based on the Overall Treatment Evaluation) suggested a minimally clinical relevant change is 0.5 on the seven graded scales applied. The importance rating indicated that an important change in the GSRS reflux dimension and the QOLRAD dimensions is equivalent to 1.0, and a very important change to 1.5.
Conclusions: The GSRS and QOLRAD are valid questionnaires that are reliable and sensitive to change. Both questionnaires should be suitable for use in clinical trials of therapeutic interventions for patients with heartburn.