A Cross-sectional Study on the Prevalence and Extraesophageal Symptoms of Gastroesophageal Reflux Disease(GERD) in Patients With Upper GI Symptoms, Visiting the Outpatient Departments of Peripheral Hospitals in Greece

Research Site, Chania

Research Site, Rhodes

Research Site, Ioannina

Research Site, Preveza

Research Site, Áno Sýros

Research Site, Chalkidiki

Research Site, Edessa

Research Site, Kavala

Research Site, Serres

Research Site, Limnos

Research Site, Kalamata

Research Site, Kalávryta

Research Site, Moláoi

Research Site, Sparti

Research Site, Karditsa

Research Site, Larissa

Research Site, Trikala

Research Site, Volos

Research Site, Komotini