The varenicline group ( n = @ ) had significantly higher continuous abstinence rates during weeks @ through @ vs the placebo group ( n = @ ) ( @ % for the varenicline group vs @ % for the placebo group ; risk difference ( RD ) , @ % -LSB- @ % CI , @ % -@ % -RSB- ; relative risk ( RR ) , @ -LSB- @ % CI , @-@ @ -RSB- ) .