Date	Event	Description
17 August 2009	New search has been performed	We updated review. We did not identify any new included studies, but implemented new methodological features of RevMan 5 such as the risk of bias table. This did not change the overall conclusions of the review.
22 October 2008	Amended	Converted to new review format.
23 February 2005	New citation required and conclusions have changed	Substantive amendment