Validation and Diagnostic Usefulness of Gastroesophageal Reflux Disease Questionnaire in a Primary Care Level in Mexico

Background/Aims Different non-invasive diagnostics strategies have been used to assess patients with gastroesophageal reflux. Gastroesophageal reflux disease (GERD) questionnaire (GerdQ) is a 6-item, easy to use questionnaire that was developed primarily as a diagnostic tool for GERD in primary care. Our aim was to validate and assess diagnostic utility of GerdQ questionnaire in Mexican patients in the primary care setting. Methods The study was performed in 3 phases: (1) a questionnaire translation and comprehension study (n = 20), (2) are a reproducibility and validation study (50 patients and 50 controls) and (3) a study to assess the clinical utility in 252 subjects with GERD symptoms. Diagnostic accuracy was calculated using endoscopy and/or pH-metry as the gold standard. Results Internal consistency measured by the Cronbach's alpha coefficient was 0.81 for patients and 0.90 for healthy controls, with a mixed coefficient of 0.93. Reproducibility for GerdQ was very good and its discriminating validity was 88%. Most of the patients with erosive reflux and non-erosive reflux with abnormal pH-metry had scores > 8, meanwhile most of the patients with functional heartburn and hypersensitive esophagus had < 8. Sensitivity, specificity and positive predictive value of GerdQ compared to the gold standard were 72%, 72% and 87%, respectively. Conclusions In Mexico, the GerdQ questionnaire Spanish validated version is useful for GERD diagnosis in the primary care setting.