Validation of the Reflux Disease Questionnaire for a Turkish Population

Background and Aims: Achieving the correct diagnosis and therapeutic success in gastroesophageal reflux disease (GERD) depends on the patient‘s self-assessment. Therefore, valid and reliable patient-reported questionnaires are very important. When designing such measurement tools, researchers should focus on their validity, reliability, sensitivity, and, applicability. The reflux disease questionnaire (RDQ) largely meets these important requirements. This study aims to examine The RDQ’s psychometric characteristics for the Turkish society (RDQ TR ) and its validity in symptoms’ evaluation. Methods: The sample of this study comprised 81 patients who were admitted to our institution, GERD study group outpatient clinic. The data collection forms used in the study were the case report forms and RDQ. Three weeks after the first interview, 30 patients were re-interviewed by the phone and the RDQ was re-administered. For the validity studies of the scale, language validity, content validity, and construct validity studies were used, and for the reliability studies, internal consistency and test-retest reliability methods were used. Results: The content validity index of form was 0.95 (0.93-0.98). The performed factor analysis indicated 3 factors with an eigenvalue over 1.0. Those factors were responsible for 77.66% of the variance. The Cronbach‘s alpha values were 0.88 for regurgitation sub-dimension, 0.91 for dyspepsia sub-dimension, 0.86 for heartburn sub-dimension, and 0.92 overall. Intraclass correlation coefficient value of the scale was 0.94. Conclusions: Our study highlights that the RDQ TR is reliable, valid, and responsive to change in Turkey patients with GERD symptomatology.