Date	Event	Description
16 May 2013	Amended	Minor change made to labelling on forest plot.
14 March 2012	New citation required and conclusions have changed	Safety profile modified, as new possible cardiovascular and psychiatric adverse events information incorporated. Efficacy findings unchanged but confirmed.
14 March 2012	New search has been performed	Seven new included studies (5 varenicline, 1 cytisine, 1 dianicline) and 14 new excluded studies added, plus safety data.
13 January 2011	Amended	Vinnikov trial of cytisine added to Studies awaiting Classification, for inclusion in next update.
8 November 2010	New search has been performed	Six new RCTs added; sources of funding added for all trials. Ongoing trials section expanded.
8 November 2010	New citation required and conclusions have changed	Surveillance data and secondary analyses do not support fears about safety. Efficacy conclusions strengthened but unchanged.
17 July 2008	Amended	Date of last search amended (2007 corrected to 2008); Source of support added.
12 May 2008	New citation required and conclusions have changed	Three new included trials, switch in the MA metric from OR to RR, updated background section and new safety information.
15 March 2008	New search has been performed	New search conducted.
30 August 2007	Amended	Converted to new review format.
15 November 2006	New citation required and conclusions have changed	Substantive amendment.