Type of study	Example references	Sample data of interest
Editorials or Commentaries	Tovey et al. (2016)	Justification for replication: replication plays an important role in science and the determination of truth, and for good reason. Cochrane and Campbell researchers invest heavily in quality assurance processes to reduce the need for duplication of effort and research waste, but given the contentious nature of this area, this replication is probably justified. The results of these two independently conducted reviews are now clear and consistent.
Policy statements	Cochrane webpage: new reviews: https://community.cochrane.org/review‐production/production‐resources/proposing‐and‐registering‐new‐cochrane‐reviews	Policy on replication: make sure your proposal does not duplicate any work already published or registered with Cochrane.
		Search the Cochrane Library for any published protocols or reviews related to your topic of interest.You can also search the Cochrane website 'Our evidence' section. This will identify published protocols and reviews, with links to the Cochrane Library, as well as the titles of reviews that have been registered and commenced, but do not yet have published protocols.
Cohort of systematic reviews (editorial)	Petticrew et al. (2017)	Justification for replication: assessments of the effects of alcohol advertising restrictions which focus only on sales or consumption are insufficient and may be misleading. Previous systematic reviews contribute important, but incomplete representations of “the evidence” needed to inform the public health case for policy decisions on alcohol advertising.
		Methods and strategies for replication: a wide evidence base needs to be drawn on to provide a system‐level overview of the relationship between alcohol advertising, advertising restrictions and consumption.
Surveys of replication	Siontis et al. (2013)	Of 73 eligible meta‐analyses published in 2010:
		49 (67%) had at least one other overlapping meta‐analysis (maximum 13); in 17 topics, at least one author was involved in at least two of the overlapping meta‐analyses; no characteristics of the index meta‐analyses were associated with the potential for overlapping meta‐analyses among pairs of overlapping meta‐analyses in 20 randomly selected topics.