title: Sequential vs. prolonged 14-day triple therapy for Helicobacter pylori eradication: the meta-analysis may be influenced by 'geographical weighting'.
abstract: BACKGROUND
  Sequential therapy is a first-line regimen obtaining satisfactory Helicobacter pylori eradication. Triple therapy prolongation improves the success rate even if a recent meta-analysis showed satisfying results only for the 14-day regimen. Studies from Africa and North America were unavailable in previous meta-analyses.
  
  
  OBJECTIVE
  To perform a meta-analysis comparing sequential vs. prolonged 14-day triple therapy with regard to 'geographic weighting' by considering subgroups analysis according to metronidazole/clarithromycin low and high resistance areas.
  
  
  METHODS
  Based on PRISMA recommendations, we considered all first-line clinical studies from 2003 to November 2014. Randomised clinical trials (RCTs) were included by a search on PubMed, MEDLINE, Science Direct, EMBASE. Data on eradication rates were expressed as ITT. Risk ratio (RR), pooled RR and 95% confidence intervals were calculated by the Mantel-Haenszel method. Data were entered into RevMan 5.2 software (Nordic Cochrane Centre) using a random-effects model.
  
  
  RESULTS
  Databases identified 194 studies; seven met the inclusion criteria. Overall results showed a similar effectiveness of the two regimens considered (RR = 0.99; 95% CI = 0.94-1.05; p = 0.75). In areas with high resistance to clarithromycin, sequential was superior to 14-day triple therapy (RR = 0.95; 95% CI = 0.90-1.00; p = 0.03). In areas with high metronidazole resistance, sequential and 14-day triple therapy were equivalent (RR = 0.99; 95% CI = 0.91-1.08; p = 0.82).
  
  
  CONCLUSIONS
  'Geographic weighting' could be the main factor affecting the lack of differences between sequential and 14-day triple therapy outcomes.
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Losurdo
authors.affiliation: Gastroenterological Department, IRCCS "De Bellis" Hospital, Castellana Grotte, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Leandro
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Principi
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Giorgio
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Montenegro
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Sorrentino
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Ierardi
authors.affiliation: Gastroenterology Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Di Leo
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017291:Clarithromycin / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D014943:Global Health; D016481:Helicobacter Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin