| Date | Event | Description |
|---|---|---|
| 27 July 2009 | Review declared as stable | No new studies have been identified and the results of the review are unlikely to change. Therefore it has been decided to no longer update this review. Some studies previously included have been removed from the review as they were not randomised trials. |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.