| Date | Event | Description |
|---|---|---|
| 1 December 2009 | New search has been performed | The searches were updated to August 2009, two new trials have been included and the Results amended accordingly. The overall conclusions of the review remain unchanged. As part of this update the assessment of methodological quality used in earlier versions of this review has been replaced with an assessment of the risk of bias. This amendment is in response to a change in the Cochrane Collaboration's methodological guidance. The list of review authors has also been updated. |
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