This review presented a clear question and searched a range of databases to locate the relevant evidence. The inclusion criteria were not fully specified and were quite broad, which may have reduced the clarity of the review overall. Restrictions were placed on the potentially relevant studies, for example, date, publication status and language, all of which limited the pool of available evidence and may have resulted in the omission of important data and introduced language/publication bias into the review. No information on the study selection and data extraction processes were reported, which made it difficult to rule out errors and biases in the review process. A narrative synthesis was carried out, which was likely to be have been appropriate given the varying visual analogue scales and follow-up periods used in each study, but the analysis could have been more explicit. Quality assessment was carried out and discussed along with other limitations of the review. Given the identified weaknesses in this limited evidence base (two small studies), together with poor reporting of the review process, the reliability of the authors' conclusions was unclear.