Development and Psychometric Assessment of a Self-evaluation Questionnaire for Gastroesophageal Reflux Disease

BACKGROUND/AIMS: There is uncertainty about how to measure outcomes reported by patients in gastroesophageal reflux disease (GERD). This study was conducted to develop an instrument and to determine of the definition of respondent for a patient reported outcomes to assess the efficacy of a treatment used for GERD treatment. METHODS: A structural process has developed a self-evaluation questionnaire for GERD (SEQ-GERD); health-related quality of life questionnaire for GERD (GERD-QOL) was translated through cross-cultural validation. Two-week reproducibility was evaluated and construct validity was assessed by correlating the SEQ-GERD with the Patient Assessment of Gastrointestinal Disorders (PAGI-SYM), the reflux disease questionnaire (RDQ), and GERD-QOL. Changes in SEQ-GERD scores were compared to assess the discriminative validity following 4 weeks of proton pump inhibitor administration. RESULTS: A total of 83 Korean patients were included (mean age 46 ± 14 years, females 61.4%). The internal consistency of the 19-item SEQ-GERD was good (alpha = 0.60–0.94) and the test–retest reliability was high (intra-class correlation coefficient = 0.67–0.95). The SEQ-GERD highly correlated with the GERD domain of the PAGI-SYM (correlation coefficient r = 0.894, P < 0.001), the RDQ-GERD (r = 0.877, P < 0.001), and GERD-QOL (r =−0.536, P < 0.05). SEQ-GERD scores significantly varied according to the overall treatment effectiveness scale of drug responsiveness and significantly decreased after drug treatment (mean differences according to the overall treatment effectiveness scale, P = 0.020). CONCLUSION: This study supports that SEQ-GERD is reliable and valid, and can be used to evaluate the treatment response in patients with GERD.