Many persons who suffer from GERD report additional symptoms, e.g., chest pain, dyspepsia, dysphagia, that are often not measured in clinical trials even though they may be distressing to the GERD sufferer. The primary goal of this study was to develop and assess the psychometric characteristics of a new GERD symptom scale measuring frequency, severity, and distress. The GERD Symptom Assessment Scale (GSAS) was administered to a sample of 169 GERD sufferers at baseline and two weeks. Internal consistency, construct validity, and test-retest reliability were assessed. Responsiveness was evaluated using clinical trial data assessing drug efficacy.
Results: Internal consistency was >0.80 for the symptom severity and distress scales. All three scales showed stability over two weeks (ICC >0.70). Both validity hypotheses were supported. Comparison of effect sizes showed the GSAS is sensitive to changes in severity of symptoms. In conclusion, the GSAS is a reliable, valid, and responsive measure of GERD symptoms.