CRD summary: This review aimed to compare the clinical efficacy of moxifloxacin to that of antibiotic regimens routinely used to treat exacerbations of chronic bronchitis. The authors concluded that the clinical success rate tends to be higher for moxifloxacin than for standard antibiotic treatments. However, methodological concerns, especially about the validity of the pooled estimate, suggest that the reliability of the authors conclusions is unclear.

CRD commentary: The review addressed a clearly defined research question. Relevant sources were searched; however, an additional search of other sources (e.g. databases that focus on drug-related subjects) would have been desirable. Attempts were made to retrieve unpublished studies, thus limiting the potential of publication bias. It was unclear whether attempts were also made to prevent further error or bias in the review process. The authors presented some details of the included studies but more detailed information about the outcome measurement (clinical and bacteriological success) would have been desirable. It appears that the validity of the included studied was not assessed and taken into account in the evidence synthesis. The authors' conclusions reflect the evidence presented. However, given the potential methodological limitations identified, the extent to which these are reliable is unclear.