Study designs of evaluations included in the review
Randomised controlled trials were eligible for inclusion.
Specific interventions included in the review
Studies of any broad-spectrum antibiotic, including metronidazole, ciprofloxacin and cotrimoxazole were eligible for inclusion. Studies of antimycobacterial agents were not eligible for inclusion. The included studies evaluated metronidazole, cotrimoxazole and ciprofloxacin, and combinations of metronidazole and cotrimoxazole, and of metronidazole and ciprofloxacin. The dosage varied between trials and treatment duration ranged from 2 to 24 weeks. In some, but not all included trials, participants were treated with concomitant medication. Studies had to include a control arm that received placebo to be eligible for inclusion.
Participants included in the review
Participants of any age or either gender, with active luminal Crohn's disease, were eligible for inclusion. The mean age of participants in the included studies ranged from 27.5 to 43.5 years, and 42% were male.
Outcomes assessed in the review
Studies evaluating clinical improvement were eligible for inclusion. This was defined as response, remission, or improvement in clinical and/or laboratory findings. The included trials used different definitions of clinical improvement. Studies that evaluated microbial overgrowth, adverse effects of antibiotic therapy, or the efficacy of antibiotics in preventing post-operative recurrence of Crohn's disease were not eligible for inclusion.
How were decisions on the relevance of primary studies made?
Three reviewers independently made decisions on the relevance of studies identified by the search. Any disagreements were resolved by discussion and consensus.