title: Systematic review: Helicobacter pylori and the risk of upper gastrointestinal bleeding risk in patients taking aspirin.
abstract: BACKGROUND
  Aspirin is widely used to modify the risk of recurrent vascular events. It is, however, associated with increased upper gastrointestinal bleeding risk. The influence of Helicobacter pylori on this risk is uncertain.
  
  
  OBJECTIVE
  To determine the influence of H. pylori on upper gastrointestinal bleeding risk in patients taking aspirin.
  
  
  METHODS
  MEDLINE and EMBASE databases were searched. All studies providing data regarding H. pylori infection in adults taking aspirin and presenting with upper gastrointestinal bleeding were included.
  
  
  RESULTS
  A total of 13 studies that included 1 case-control, 10 cohort studies and 2 randomized-controlled trials (RCTs) were analysed. The case-control study (n = 245) determined H. pylori to be a significant independent risk factor for upper gastrointestinal bleeding. The cohort studies were heterogeneous, varying in inclusion criteria, doses and duration of aspirin used, mode of H. pylori testing and causative GI pathology considered. Comprising 5465 patients, H. pylori infection was tested for in 163 (0.03%) aspirin users with upper gastrointestinal bleeding. The RCTs yielded no significant results.
  
  
  CONCLUSIONS
  The current data are not sufficient to allow meta-analyses. The widely held belief that H. pylori is a risk factor for upper gastrointestinal bleeding in regular aspirin users is not supported by the very limited evidence available.
authors.affiliation: Institute for Ageing and Health, Newcastle University, UK. e.h.fletcher@ncl.ac.uk
authors.forename: E H
authors.initials: EH
authors.lastname: Fletcher
authors.forename: D E
authors.initials: DE
authors.lastname: Johnston
authors.forename: C R
authors.initials: CR
authors.lastname: Fisher
authors.forename: R J
authors.initials: RJ
authors.lastname: Koerner
authors.forename: J L
authors.initials: JL
authors.lastname: Newton
authors.forename: C S
authors.initials: CS
authors.lastname: Gray
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D001241:Aspirin / Q000009:adverse effects*; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced*; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D041742:Upper Gastrointestinal Tract
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin