| Date | Event | Description |
|---|---|---|
| 12 January 2016 | New citation required but conclusions have not changed | Compared with the 2006 version of this review, a substantial amount of new information has been included, but there is no change to the main conclusions in this updated review. |
| 12 January 2016 | New search has been performed | We have updated the searches to July 2015. We included 26 new trials (1889 participants) in this version. There are now 31 trials, with 2257 participants, included in this updated review. |
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.