Date	Event	Description
15 December 2011	New search has been performed	Issue 2, 2012: Electronic searches were updated, risk of bias tables have been completed for all included trials and text modified. A new author joined the review team to help with updating the review.
15 December 2011	New citation required but conclusions have not changed	Issue 2, 2012: Three new trials were included in the update (Arora 2011; Mahdy 2010; Prajna 2010).
22 October 2008	Amended	Converted to new review format.
13 November 2007	New citation required and conclusions have changed	Substantive amendment