title: Risk factors for Barrett's oesophagus: a population-based approach.
abstract: OBJECTIVE
  Given its often subclinical course, Barrett's oesophagus (BO) hardly lends itself to epidemiologically stringent evaluations. The objective of this study was to investigate risk factors for incident BO diagnosed in a defined population in southeast Sweden while paying particular attention to epidemiological aspects of the study design.
  
  
  METHODS
  Consecutive patients (aged 18-79 years) who were endoscoped with new indications at units exclusively responsible for all gastroscopies in defined catchment area populations were invited to take part in the study. Biopsies were taken above and immediately below the gastro-oesophageal junction, and exposure information was collected through self-administered questionnaires. Endoscopy-room-based cross-sectional data from 604 patients were supplemented with exposure data from 160 population controls. Associations, expressed as odds ratios (ORs), were modelled by means of multivariable logistic regression.
  
  
  RESULTS
  In the comparison with population controls, reflux symptoms and smoking indicated a 10.7- and 3.3-fold risk, respectively, for BO (95% confidence interval (CI) 3.5-33.4 and 1.1-9.9, respectively). Body mass was unrelated to risk. In the cross-sectional analysis among endoscopy-room patients, reflux symptoms were associated with an OR of 2.0 (95% CI 0.8-5.0). This association was, however, modified by the subjunctional presence of Helicobacter pylori; although the infection was not in itself significantly connected with risk, a combination of reflux symptoms and H. pylori infection was linked to an almost 5-fold risk (95% CI 1.4-16.5) as compared with the absence of both factors. The BO prevalence increased by 5% per year of age (95% CI 1-9%).
  
  
  CONCLUSIONS
  Reflux is the predominant risk factor for BO, and proximal gastric colonization of H. pylori seems to amplify this risk.
authors.affiliation: Department of Surgery, Kalmar County Hospital, Sweden. Johan.Johansson@ki.se
authors.forename: Johan
authors.initials: J
authors.lastname: Johansson
authors.forename: Hans-Olof
authors.initials: HO
authors.lastname: Håkansson
authors.forename: Lennart
authors.initials: L
authors.lastname: Mellblom
authors.forename: Antti
authors.initials: A
authors.lastname: Kempas
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Johansson
authors.forename: Fredrik
authors.initials: F
authors.lastname: Granath
authors.forename: Olof
authors.initials: O
authors.lastname: Nyrén
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001471:Barrett Esophagus / Q000453:epidemiology* / Q000473:pathology; D001706:Biopsy; D002391:Catchment Area, Health; D003430:Cross-Sectional Studies; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012189:Retrospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology