[From the Cochrane Library: the use of peer review is still under discussion]

Peer review is generally considered to be an invaluable part of the editorial process of biomedical journals. It is widely assumed that peer review has positive effects on the quality of submitted papers and of biomedical research. This is why improvements in peer reviewing have been studied for some years. According to the authors of a recent Cochrane methodology review, peer review does improve the quality of papers, but there is insufficient evidence that it also improves the quality of biomedical research. A major study on this subject is called for, since its results could have implications for patient care and scientific research.