Date	Event	Description
25 August 2015	New search has been performed	The search was updated in November 2014 We found four new studies, of which we excluded three and one is ongoing We updated the introduction We updated the methodology We repeated the analysis We graded the evidence according to actual standards We updated the discussion We included a 'Summary of findings' table and full 'Risk of bias' tables
25 August 2015	New citation required and conclusions have changed	New review authors updated this review; see Published notes for an explanation of why conclusions have changed even though the number of included studies is the same as in the original review (Davison 2007)