International Validation of ReQuest™ in Patients with Endoscopy-Negative Gastro-Oesophageal Reflux Disease

Abstract

Background: Reflux Questionnaire (ReQuest™), a newly developed gastro-oesophageal reflux disease-sensitive scale, can be used to reliably evaluate the effect of treatment on gastro-oesophageal reflux disease symptoms. Aim: International validation of this scale, in patients suffering from endoscopy-negative gastro-oesophageal reflux disease. Methods: In this open, multicentre and multinational clinical trial 840 endoscopy-negative gastro-oesophageal reflux disease patients received pantoprazole 20 mg daily for 28 days. The long and short versions of ReQuest™ were completed both in the pre-treatment and treatment phases. For scale development an item reduction analysis was performed. Internal consistency, test–retest reliability and responsiveness were calculated for psychometric analysis. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale and the Psychological General Well-being questionnaire by means of correlation coefficients. Results: Factor analyses confirmed the content validity of both long and short version of ReQuest™. Psychometric calculations proved high internal consistency (Cronbach’s alpha: 0.9), test–retest reliability [Intraclass Correlation Coefficient: 0.9 (long vs. long) and 0.8 (short vs. short)], and responsiveness (Responsiveness Index 320.3) of the scale, for which also good construct validity was achieved (correlation coefficient: Gastrointestinal Symptom Rating Scale 0.6; Psychological General Well-being –0.4). Conclusion: ReQuest™ proved valid, reliable, and responsive in this multinational clinical trial to evaluate treatment response in endoscopy-negative gastro-oesophageal reflux disease patients.