Prospective studies that compared an oral macrolide antibiotic (with or without additional therapy) to any non-macrolide comparator in adults with chronic rhinosinusitis were eligible for inclusion. Participants had to meet specified diagnostic criteria (details in the review). Studies had to report disease-specific or symptom-based outcomes.
The included studies compared clarithromycin plus additional therapy with an active comparator; and azithromycin and roxithromycin with placebo. Treatment duration was three weeks for clarithromycin and 12 weeks for the other macrolides.
Final study selection was done by two reviewers. Disagreements were resolved by discussion to reach consensus.