[Epidemiology of gastro-esophageal reflux disease]

Gastroesophageal reflux disease(GERD) is believed to be common and chronic gastrointestinal disorder. Quantitative estimates of the actual prevalence of GERD are difficult to obtain, because those who seek health care probably represent only a tip of the iceberg of people with GERD. The prevalence of heartburn and/or regurgitation, considered to be reasonably specific symptoms for the diagnosis of GERD, ranged from 10% to 48% for heartburn, from 9% to 45% for regurgitation and 21% to 59% for both/either in systematic review of GERD and reflux esophagitis(RE). It is widely accepted that the prevalence is lower in Asian countries, including Japan, compared with that in Western countries. However, the prevalence of RE in Japan may be increasing. In the case of heartburn and regurgitation in GERD and endoscopic findings in RE, different understandings of these terms by different investigators and subjects may have contributed to the range of results. Symptom definitions and what is understood by them should be among the most important considerations when undertaking population prevalence studies on reflux like symptoms, to allow comparisons to be made between studies.