| Date | Event | Description |
|---|---|---|
| 13 June 2012 | New search has been performed | New searches run January 2012. |
| 13 June 2012 | New citation required but conclusions have not changed | We identified no new studies which met the inclusion criteria for the review following updated searches in January 2012. We excluded three further studies (Holgers 2011; Jalali 2009; Roberts 2011). There are therefore no changes to the conclusions of the review. |
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