Study designs of evaluations included in the review
Randomised controlled trials (RCTs) were eligible for inclusion. Crossover trials appeared to have been excluded. The trials had to include intention-to-treat analysis. For the secondary analyses, prospective studies including randomised and non-randomised trials were eligible for inclusion.
Specific interventions included in the review
Studies that compared levofloxacin-based triple therapy (levofloxacin, amoxicillin and proton-pump inhibitor) with bismuth-based quadruple therapy (bismuth, tetracycline and metronidazole, plus either rabeprazole, pantoprazole, omeprazole or lansoprazole) were eligible for inclusion. Details of drug dosages were provided. The duration of treatment in both treatment groups was either 7 or 10 days.
Participants included in the review
Participants with persistent H. pylori infection and confirmed treatment failure to at least one prior course of standard triple therapy (as measured by urea breath testing or gastric mucosal biopsy) were eligible for inclusion.
Outcomes assessed in the review
The main outcome assessed was the eradication of H. pylori infection at least 4 weeks after treatment, as confirmed by urea breath testing or gastric mucosal biopsy. Other outcomes assessed were the incidence of adverse events and the incidence of therapy discontinuation due to adverse events. The secondary outcomes included eradication rates with 7 days of therapy versus 10 days of therapy, and eradication rates with levofloxacin 250 mg twice daily versus 500 mg once daily.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.