Key points are not available for this paper at this time.
More than 5500 systematic reviews, at various stages of completion, are currently available in the Cochrane Library (www.cochrane.org1) and 9000 systematic reviews are critically appraised for validity in the Database of Abstracts of Reviews of Effectiveness, or DARE (www.crd.york.ac.uk2).
Straus et al. (Mon,) studied this question.