Diagnostic Validity of the Korean Gastrointestinal Symptom Rating Scale (KGSRS) in the Assessment of Gastro-Esophageal Reflux Disease

Background: Gastro-esophageal reflux disease(GERD) is increasing in Asian countries, but the majority of patients does not present with endoscopic abnormalities, the assessment of the symptom severity and quality of life, and their response to treatment, have become increasingly important. Our objectives were to develop and evaluate a questionnaire about Health-related quality of lif (HRQOL) related with gastrointestinal symptoms in patients with GERD. Methods: Eighty eight, consecutive patients with GERD and 174 healthy subjects were enrolled in the study. GERD was defined by the presence of reflux symptom that are heartburn and acid reflux with occurring more than once per week with/without endoscopic reflux esophagitis. All subjects were examined with endoscopy and performed self-reported questionnaires that were modified Korean form of gastrointestinal symptom rating scale(KGSRS), newly developed instrument, and KSF-36(Korean version of Medical Outcomes Study Short Form), a conventional one. We compared the score of KGSRS between response group and non-response group after 2-weeks omeprazole trial for evaluation of discriminative validity of KGSRS. Results: Internal consistency for the KGSRS scales range from 0.58-0.84. The repeatability was confirmed by test-retest results(Pearson's correlation coefficients= 0.62-0.80, p< 0.01). The KGSRS scale scores were significantly correlated with those of KSF-36. It revealed construct validity. The total score of KGSRS in patients with GERD was significantly lower than control(376.1 +/- 51.3 vs. 433.5 +/- 42.0, p= 0.000). There were significant differences for 4 symptom complex except diarrhea between response group and non-response group. Conclusion: The KGSRS has good reliability and construct validity and discriminates symptom severity and frequency of patients with GERD.