| Date | Event | Description |
|---|---|---|
| 12 February 2013 | New search has been performed | Searches were rerun but no new studies were identified for inclusion or exclusion. |
| 12 February 2013 | New citation required but conclusions have not changed | Searches were rerun but no new studies were identified for inclusion or exclusion. Minor copy edits made to the text. One author stepped down from author team. |
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