| Date | Event | Description |
|---|---|---|
| 6 November 2017 | New citation required but conclusions have not changed | No new studies identified for inclusion. Text updated as required and summary of findings tables added. |
| 7 February 2017 | New search has been performed | New searches run. |
| 5 June 2013 | Amended | Minor amendment to PLS |
| 29 May 2013 | New citation required but conclusions have not changed | Two studies added but conclusions remain unchanged. |
| 5 May 2013 | New search has been performed | Review updated, new searches run and text revised. |
| 5 August 2010 | Amended | EMBASE search strategy added. |
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