RESUMEN
<p><b>BACKGROUND</b>Symptoms, endoscopy, and pH monitoring form the basis of diagnosis of gastroesophageal reflux disease (GERD). Their relationship was meaningful for primary care physicians, but still unclear. Our research aimed to compare questionnaire, endoscopy, and pH monitoring and to analyze their correlations.</p><p><b>METHODS</b>Three hundred patients who underwent the Reflux Disease Questionnaire (RDQ), endoscopy, and esophageal 24-hour pH monitoring from March 2007 to December 2010 in Peking University People's Hospital were enrolled. We analyzed the characteristics of different investigations and their relationships.</p><p><b>RESULTS</b>Male (OR for mild reflux esophagitis (RE) = 2.433, severe RE = 8.386), body mass index (BMI) (OR for mild RE = 1.222, severe RE = 1.297), and hernia (OR for mild RE = 6.059, severe RE = 17.547), were found to be the risk factors for RE; age (OR = 1.074) was correlated with severe RE. The consistency of questionnaire, endoscopy, and pH monitoring was poor: RDQ did not agree well with pH monitoring (κ = 0.061), nor with endoscopy (κ = 0.044); pH monitoring did not agree well with endoscopy (κ = 0.316). However, the severity of mucosa injury in RE was associated with pathological acid exposure (PAE): reflux episodes of >5 minutes (P = 0.035), the percentage time pH <4 (P = 0.017), and the DeMeester score (P = 0.016) increased significantly in patients with severe RE. Chest pain had poor relationship with RE or PAE.</p><p><b>CONCLUSIONS</b>Male, age, BMI, and hernia were probably risk factors for esophagitis. RDQ, endoscopy, and pH monitoring have their own focus and reinforce each other in diagnosis. Of the GERD symptoms, chest pain had negative correlation with RE or PAE.</p>