Evaluation of GERD symptoms during therapy Part II. Psychometric evaluation and validation of the new questionnaire ReQuest (TM) in erosive GERD

Background/Aims: Evaluation of the response of gastroesophageal reflux disease (GERD) symptoms to treatment would be facilitated by a brief, valid, reliable and responsive, self-assessed GERD-sensitive scale. We therefore developed the Reflux Questionnaire (ReQuest (TM)). This publication describes the psychometric evaluation and validation of ReQuest (TM). Methods: This second phase of development was based on data from a clinical trial of patients with erosive GERD who received pantoprazole 20 or 40 mg daily for 28 days and completed weekly the long, and daily the short version of ReQuest (TM). The psychometric analyses of ReQuest (TM) included internal consistency, test-retest reliability and responsiveness. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) scale. Results: Validation of ReQuest TM indicated very high internal consistency (Cronbach's alpha = 0.90) and test- retest reliability (intraclass correlation coefficient 0.94 (long- long) and 0.86 short-short)). This was also the case for the two subscales ReQuest (TM) -GI and ReQuest (TM)-WSO with Cronbach's alpha coefficients of 0.84 and 0.81. Responsiveness was high with a responsiveness index of > 0.8 at day 28. Construct validity was good. Conclusion: ReQuest (TM) is a highly reliable, valid and responsive self- assessment tool for evaluating treatment response in patients with erosive GERD, and can be applied daily.