When is systematic review replication useful, and when is it wasteful?

Abstract

To the Editor, During the past quarter of a century and following the global explosion in access to scientific literature, systematic reviews have become an excellent way to inform decisions with summaries of the effects of interventions, and to learn about their impact under different conditions or among populations. Systematic reviews play a key role in ensuring that policy decisions are informed by research. Local and national governments as well as international health organizations now regularly commission and request that systematic reviews inform policy decisions. [...]