Thursday 16 June 2011

Funded by Cochrane Opportunities Fund 2010

Users rely on Cochrane reviews to make decisions about health and social care.

As of 15 August 2010, 376 (8.7%) of Cochrane reviews contained no included studies.

An “empty review” is defined as a systematic review that reports no studies eligible for inclusion.

Within the CDSR, the number of empty reviews is increasing and is inconsistent across Review Groups.

2010 accounts for reviews published through 15 August 2010 only

Empty reviews are important as they:◦ Tell us who is undertaking the review and thus

interested in the topic.◦ Highlight major research gaps.◦ Indicate the state of the evidence at a point in

time.◦ Justify further research and/or funding.◦ Highlight potential harms.

In the absence of included studies some authors use evidence from excluded studies for reporting implications for practice: ◦ basing their recommendations on the “available

evidence” not necessarily the best “evidence”.

At present there is little guidance for reporting

excluded studies in the Cochrane Handbook for Systematic Reviews of Interventions. ◦ There is no guidance for reporting of empty reviews.

To examine the way in which empty Cochrane reviews are reported.

To review current guidelines for reporting of empty reviews.

To develop more explicit guidance for the conduct and reporting of empty reviews.