Received: 31 October 2016
Accepted: 23 March 2018
First Online: 5 April 2018
Ethics approval and consent to participate
: The study protocol was approved by the Ethics Committee for Medical Research on Human Beings of the Clinical Hospital of the University of São Paulo Medical School (SDC 4024/14/004). Signed informed consent will be obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests. JSI is the Principal Site Investigator in Varenicline Trials promoted by Pfizer.
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