| Date | Event | Description |
|---|---|---|
| 31 March 2009 | Feedback has been incorporated | Feedback incorporated into review. |
| 19 March 2009 | New search has been performed | Searches conducted. No new trials were included or excluded. |
| 3 January 2008 | Amended | Converted to new review format. |
| 17 March 2005 | New citation required but conclusions have not changed | Yang Huiming, Wan Chaomin and Mao Meng took over this review from D'Souza RM and D'Souza R and updated it. |
| 17 March 2005 | New search has been performed | Searches conducted. |
| 2 January 2000 | New search has been performed | Searches conducted. |
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