| Date | Event | Description |
|---|---|---|
| 2 July 2013 | New search has been performed | Searches updated but no new studies were identified for inclusion. |
| 2 July 2013 | New citation required but conclusions have not changed | Review text and 'Summary of findings' table added. Our conclusions remain unchanged. |
| 31 January 2011 | New search has been performed | Searches updated and one new trial included (Cam 2002). The conclusions remain unchanged. |
| 14 March 2005 | New search has been performed | Searches conducted. |
| 12 December 2002 | New search has been performed | Searches conducted. |
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