title: Prevalence of Barrett's Esophagus in Asian Countries: A Systematic Review and Meta-analysis.
abstract: OBJECTIVE
  The prevalence and risk factors of Barrett's esophagus (BE) in Asian countries are unclear. Studies report a wide range of BE prevalence in Asian countries. We conducted a systematic review and meta-analysis to examine the prevalence of BE and its temporal changes and risk factors in Asian countries.
  
  
  METHODS
  Two investigators performed independent literature searches by using PubMed and EMBASE databases, and subsequent data abstraction for studies had to meet several set inclusion and exclusion criteria. Pooled BE prevalence was calculated by using a random-effect model. Estimates of relative risk for possible risk or protective factors were also calculated.
  
  
  RESULTS
  A total of 51 studies (N = 453,147), mainly from Eastern Asia, were included. The pooled prevalence of endoscopic BE was 7.8% (95% confidence interval, 5.0-12.1; 23 studies) and of histologically confirmed BE was 1.3% (95% confidence interval, 0.7-2.2; 28 studies). Most of histologic BE (82.1%) was short-segment BE (<3 cm). There was a trend toward an increase in prevalence of BE over time from 1991 to 2014, especially in Eastern Asian countries. Within BE cohorts, pooled prevalence of low-grade dysplasia, high-grade dysplasia, and esophageal adenocarcinoma was 6.9%, 3.0%, and 2.0%, respectively. Reflux symptoms, male sex, hiatus hernia, and smoking were associated with a significantly increased risk of histologic BE in patients with BE compared with patients without BE. However, half of the patients with histologic BE did not have reflux symptoms.
  
  
  CONCLUSIONS
  BE is not uncommon in Asian countries and seems to share similar risk factors and potential for neoplastic progression to those seen in Western countries.
authors.affiliation: Section of Gastroenterology and Hepatology, Department of Medicine, Michael E. DeBakey VA Medical Center, and Baylor College of Medicine, Houston, Texas.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiota
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Singh
authors.affiliation: Section of Gastroenterology and Hepatology, Department of Medicine, Michael E. DeBakey VA Medical Center, and Baylor College of Medicine, Houston, Texas.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Anshasi
authors.affiliation: Section of Gastroenterology and Hepatology, Department of Medicine, Michael E. DeBakey VA Medical Center, and Baylor College of Medicine, Houston, Texas. Electronic address: hasheme@bcm.edu.
authors.forename: Hashem B
authors.initials: HB
authors.lastname: El-Serag
mesh_terms: D000328:Adult; D001208:Asia / Q000453:epidemiology; D001471:Barrett Esophagus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors
keywords: Barrett’s Esophagus; Meta-analysis; Prevalence; Risk Factors; Systematic Review