| Date | Event | Description |
|---|---|---|
| 9 July 2013 | New citation required but conclusions have not changed | No new conclusions made to the review after results of 2012 update search added |
| 18 March 2013 | New search has been performed | Review update completed: seven new studies identified in update search, each of which was excluded with reasons. ‘Summary of findings’ table added to grade the quality of the evidence. New format ‘Risk of bias’ tables have been constructed, with new ratings applied |
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