Date	Event	Description
15 June 2010	Amended	Contact details updated.
22 October 2009	New search has been performed	The review has been updated, a new search undertaken and an additional 8 studies have been included. Although the overall conclusions of the review have not changed, the aggregated values for most outcomes have changed.
22 October 2009	New citation required but conclusions have not changed	A new author has joined the review team as first author.
14 August 2007	New citation required and conclusions have changed	Substantive amendment