McCaffery et al¹ conclude that "antistaphylococcal treatment achieves sputum clearance of Staphylococcus aureus in patients with cystic fibrosis . . ." and that prophylactic treatment in young children is ". . . likely to be of clinical benefit". These positive conclusions are based on the results of a study which has important methodological problems. Neither the introduction nor the methods section of this review state what hypotheses the review set out to test, the criteria used to decide whether a study was suitable for inclusion, outcomes to be studied in the review, or methods used to assess the methodological quality of included studies. Systematic reviews differ from narrative reviews in that they test hypotheses using a methodology which is well described.² The authors have described their search strategy, which is based on that developed by the Cochrane Collaboration, to identify randomised controlled trials. The authors have, however, included a number of studies in their . . . [Full text of this article]