Efficiency of searching the grey literature in palliative care.

A systematic review into palliative care team effectiveness was undertaken which has, inherent in its methodology, grey literature searching. Over 100 letters were written to a systematically chosen range of service providers, commissioners, and experts in combination with requests for information in six UK national cancer/palliative care organization newsletters. In addition, the System for Information on Grey Literature (SIGLE ) database was searched. As a result, 25 document hard copies were received. The documents were, in all but one case (this one study was also highlighted by the SIGLE search), not relevant as they were predominated by annual reports, service descriptions, and needs assessments. In terms of obtaining unpublished studies for possible inclusion in the review, this comprehensive search was unsuccessful and, therefore, it would appear that grey literature searching is not a useful tool in palliative care systematic reviews.