Date	Event	Description
14 February 2011	Amended	Link to anticoagulant feedback added
14 July 2010	New search has been performed	The review was updated, one additional trial was added to the included studies and two additional trials were excluded.
27 April 2010	New citation required but conclusions have not changed	There was a change in authors in the updated review.
20 October 2008	Amended	Converted to new review format.
14 November 2005	Amended	Minor copy edits made.
23 August 2004	New citation required but conclusions have not changed	Change in authors.
23 August 2004	New search has been performed	Review substantively updated by the addition of eight new included studies. Conclusions unchanged.
15 February 1999	New search has been performed	One additional trial included but no change to conclusions.