Dear Editor,
It is with interest that we read the meta-analysis by Chen et al. published in the June edition of International Orthopaedics [1]. Whilst we commend the authors on the amount of work that they have put into this study and congratulate them on achieving publication, it is a shame that the serious methodological issues (highlighted by previous correspondents [2, 3]) were not identified and rectified before publication.
Whilst the authors conclude that “more…RCTs with large samples” are required to answer their study question adequately, their review has not included an RCT of 1,715 patients published in the Journal of Bone and Joint Surgery (American Volume) in August 2011 examining precisely the same question [4]. On the first read of the paper, it is unclear how this may have happened given the confusion regarding inclusion and exclusion criteria, and the fact that search strings, details of excluded studies and date of last search are not reported. With the recent author response, it is made clear that the search string used was inadequately broad to detect all the relevant literature [5]. If the PRISMA guidelines had been followed, this would have been apparent to reviewers and readers and remedial action could have been taken.
Meta-analyses can provide important information and should become more important given the improvements in the quality of evidence for analysis provided by primary studies. However, there is such variation in quality of meta-analyses in orthopaedics that the use of evidence provided by such studies is increasingly being called into doubt [6]. It is now almost 14 years since the publication of the first QUORUM (now PRISMA) statement [7, 8]. Journals are in a position to take the lead in improving the quality of meta-analyses, and if they were to take the small step of insisting on studies being conducted according to the PRISMA guidelines, this would avoid many of the problems observed in studies of this type.
References
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