The research question was supported by inclusion criteria for participants, intervention, study design and outcomes. Only one electronic database was searched, the search for unpublished studies was limited and only English language studies were sought, so it is possible that relevant studies could have been missed. The authors did not state that they assessed validity of primary studies, so the reliability of their results was not known. Insufficient study details were provided for the reader to make a judgement regarding study quality. The review process was not described so it was not known whether steps were taken to reduce possible reviewer bias and error. The narrative synthesis appeared appropriate given the paucity of data included for outcomes and the different doses and regimens used. Primary study details reported did not include patient characteristics, so it was not known how heterogeneous the populations were. The authors' conclusions reflected the evidence presented, but the lack of reporting of the review process, the potential for missed studies, the paucity of data and the lack of information relating to the quality of included studies, meant that the authors' conclusions should be viewed with caution.