The Cochrane Empty Reviews Project

The first report of The Cochrane Empty Reviews Project is now available in published form from PLoS ONE (
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0036626
).  This article explores the incidence of empty systematic reviews in The Cochrane Database of Systematic Reviews (The CDSR) and describes their current characteristics.

Citation:  Yaffe J, Montgomery P, Hopewell S, Shepard LD (2012) Empty Reviews: A Description and Consideration of Cochrane Systematic Reviews with No Included Studies. PLoS ONE 7(5): e36626, doi:10.1371/journal.pone.0036626

Please post any comments/questions to this article by using the comments feature on the PLoS ONE access page.

On Wednesday, 19 October 2011, The Cochrane Empty Reviews Project held a meeting at the 19th Cochrane Colloquium in Madrid, Spain to discuss their findings regarding the reporting of empty reviews in The Cochrane Database of Systematic Reviews, review the key proceedings of a consensus meeting held in June 2011, discuss suggestions generated by the consensus group, and invite feedback.

Provided below is the link to the meeting presentation that informed the discussion:

• The Cochrane Empty Reviews Project meeting presentation at the 19th Cochrane Colloquium in Madrid

On Wednesday, 19 October 2011, The Cochrane Empty Reviews Project is holding a meeting at the 19th Cochrane Colloquium in Madrid, Spain from 18:00-19:30 to report the project findings and consensus group feedback.  We invite all interested Cochrane Collaboration contributors to participate.  The meeting room will be listed in the Colloquium program in the coming months. 

This meeting will address ways in which empty reviews are reported in The Cochrane Database of Systematic Reviews, report the key proceedings of a consensus meeting held in June 2011, discuss the suggested guidance generated by the consensus group, and invite feedback.

On Thursday, 16 June 2011, The Cochrane Empty Reviews Project convened a meeting of Cochrane Collaboration contributors to consider ways in which empty reviews are reported in The Cochrane Database of Systematic Reviews and to develop guidance for their reporting.

The meeting convenors are in the process of drafting a formal report of the meeting proceedings to be posted at a future date. In the meantime, provided below are links to some of the meeting presentations providing background to empty reviews. The content of the final presentation link also notes in red some of the meeting discussion regarding potential guidance. Please click on the links to view or download the following documents:

• The Cochrane Empty Reviews Consensus Meeting Agenda;
• The Cochrane Empty Reviews Consensus Meeting Introduction;
• Current Guidance in The Cochrane Handbook;
• Cochrane Review Group and Other Systematic Review Producing Organizations’ Policies and Perspectives of Empty Reviews;
• Preliminary Content Analysis of ‘Implications for Practice’ in Empty Reviews;
• Perspective from a CRG Publishing a Relatively High Proportion of Empty Reviews;
• Development of Views and Guidance for Empty Reviews.

Finally, you are invited to list any comments/questions for open discussion to this post.

On Thursday, 16 June 2011, The Cochrane Empty Reviews Project is convening a meeting of Cochrane Collaboration contributors to consider ways in which empty reviews are reported in The Cochrane Database of Systematic Reviews.  The format and agenda of the consensus meeting will follow that suggested by Moher et al. (2010) and used in the development of the CONSORT Statement.  The ultimate objective of The Cochrane Empty Reviews Project Consensus Meeting will be to produce either general guidance or specific guidelines for the reporting of empty reviews.

Provided below are some of the pre-meeting materials intended to inform the foundational discussion. Please click on the links to view or download the listed documents:

• The Meeting Agenda;
• Relevant excerpts from The Cochrane Handbook for Systematic Reviews of Intervention;
• A Literature Review and Descriptive Summary of Empty Reviews in The CDSR;
• Citation: Lang, A., Edwards, N., & Fleiszer, A. (2007). Empty systematic reviews: Hidden perils and lessons learned. Journal of Clinical Epidemiology, 60, 595-597; and
• Citation: Green, S., Higgins, J.P.T., Schunemann, H.J., & Becker, L. (2007). Response to paper by Lang A, Edwards N, and Fleiszer A. Journal of Clinical Epidemiology, 60, 598-599.

The Empty Reviews Project is funded by the Cochrane Opportunities Fund to develop reporting guidelines for empty reviews, or systematic reviews that report no studies eligible for inclusion.

Having examined the background literature and the current reporting practices of all empty reviews within The Cochrane Database of Systematic Reviews, the project investigators are preparing provisional guidelines for formal discussion at a consensus meeting to be held in June 2011.

The project findings and final recommendations for reporting guidelines will be presented at the 2011 Cochrane Colloquium in Madrid, Spain.

For further information regarding the Cochrane Empty Reviews Project, please view the attached from the 2010 Cochrane Colloquium in Keystone, Colorado (KeystoneOralPresentation19Oct2010) or contact the project investigators via email (cochrane.empty.reviews@gmail.com).

Paul Montgomery, PhD, University of Oxford, PI

Sally Hopewell, PhD, UK Cochrane Centre, Co-PI

Joanne Yaffe, PhD, University of Utah, Co-PI

Lindsay Shepard, MSc, University of Utah, Research Associate