| Date | Event | Description |
|---|---|---|
| 18 August 2010 | New search has been performed | Literature search run, no new studies found. |
| 13 August 2008 | New search has been performed | Literature search re‐run; no new studies were identified. |
| 17 April 2008 | Amended | Converted to new review format. |
| 3 January 2008 | New citation required and conclusions have changed | Substantive amendment |
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