Date	Event	Description
10 July 2011	New citation required and conclusions have changed	The conclusions of the review have changed from there being insufficient evidence assessing the use of prophylactic clotting factor concentrates, to there being evidence that the use of these concentrates is effective in decreasing the frequency of joint bleeds and in partially preventing or slowing down the development of arthropathy. The number of participants included in the review has increased from 37 to 142, with two new studies added. Alfonso Iorio (previously a co‐author) is now lead author on this review and Kent Stobart (previously lead‐author) is now a co‐author. John Wu has stepped down from the review and Emanuela Marchesini, Maura Marcucci and Anthony Chan are new co‐authors.
10 July 2011	New search has been performed	Two new trials have been incorporated into the review (Gringeri 2011; Manco‐Johnson 2007).
7 October 2009	Amended	Please note: We are aware that the update of this review is overdue. The original review team has stepped down and a new review team is in place and working on the update. The updated version of this review will be published in 2010.
31 October 2008	Amended	Converted to new review format.
1 February 2006	New search has been performed	The text of the Reviewers' Conclusions in the abstract has been altered to make clear that there is a lack of evidence from randomised controlled trials for the use of prophylaxis. No new references were found in the latest search for this review.