A consortium consisting of York Health Economics Consortium and the Cochrane Information Retrieval Methods Group has looked into the issue of searching for unpublished studies and obtaining access to unpublished data and has produced the following report and bibliography:

Arber M, Cikalo M, Glanville J, Lefebvre C, Varley D, Wood H. Annotated bibliography of published studies addressing searching for unpublished studies and obtaining access to unpublished data. York: York Health Economics Consortium; 2013.

This work was a sub-project of a larger project entitled “Searching for unpublished trials using trials registers and trials web sites and obtaining unpublished trial data and corresponding trial protocols from regulatory agencies”.

Other outputs of this project include:

Schroll, JB, Bero, L, Gotzsche, P. Searching for unpublished data for Cochrane reviews: Cross sectional study.  BMJ 2013;346:f2231

Wolfe, N, Gotzsche, PC and Bero, L.  Strategies for obtaining unpublished drug trial data:  A qualitative interview study.  Systematic Reviews. 2013; 2:31. http://www.systematicreviewsjournal.com/content/2/1/31

The project was a collaboration between the San Francisco Branch of the United States Cochrane Center, Nordic Cochrane Centre, Cochrane Acute Respiratory Infections Group, York Health Economics Consortium and the Cochrane Information Retrieval Methods Group. This sub-project was undertaken by staff of York Health Economics Consortium and Carol Lefebvre of Lefebvre Associates Ltd, for which some funding was provided by the Cochrane Collaboration under the Methods Innovation Funding initiative.

We thank the authors for allowing us to link to the full text of the report from this site.