| Date | Event | Description |
|---|---|---|
| 19 December 2013 | New search has been performed | New searches completed for the second update, one new study included. |
| 19 December 2013 | New citation required and conclusions have changed | One new study included in the review (Webster 2011). Conclusions updated. |
| 8 November 2010 | New search has been performed | New searches completed for the first update, one new study included in the review and risk of bias assessment completed (Saleh 2009). |
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