Psychometric validation of the German translation of the Gastrointestinal Symptom Rating Scale (GSRS) and Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire in patients with reflux disease

BACKGROUND Symptoms of heartburn has an impact on health-related quality of life (HRQL). When a questionnaire is translated into a new language, a linguistic validation is necessary but not sufficient unless the psychometric characteristics have been verified. The aim is to document the psychometric characteristics of the German translation of the Gastrointestinal Symptom Rating Scale (GSRS) and Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire. METHODS 142 patients with symptoms of heartburn (Age: M = 47.5, +/- 14.6; Males = 44.4%) completed the German translation of GSRS, the QOLRAD, the Short-Form-36 (SF-36) and the Hospital Anxiety and Depression (HAD) scale. RESULTS The internal consistency reliability of GSRS ranged from 0.53-0.91 and of QOLRAD from 0.90-0.94, respectively. The test-retest reliability of GSRS ranged from 0.49-0.73 and of QOLRAD from 0.70-0.84. The relevant domains of the GSRS and QOLRAD domain scores significantly correlated. GSRS domains of Abdominal Pain and Constipation correlated (negatively) with most of the domains of the SF-36. The relevant QOLRAD domains significantly correlated with all SF-36 domains. CONCLUSIONS The psychometric characteristics of the German translation of GSRS and QOLRAD were found to be good, with satisfactory reliability and validity. The reliability of the GSRS Abdominal Pain domain was moderate.