For a study, researchers sought to compare the effectiveness of varenicline with a placebo in African American individuals who smoke light, moderate, or heavy cigarettes on a regular basis.

Kick It at Swope IV (KIS-IV) was a randomized, double-blind, placebo-controlled clinical experiment that took place at a federally recognized health facility in Kansas City. Between June 2015 and December 2017, 500 African American adults of all smoking levels were enrolled; the last follow-up was conducted in June 2018. Participants were randomly assigned (in a 3:2 ratio) to receive varenicline (1 mg twice daily; n=300) or a placebo (n=200) for 12 weeks. Randomization was stratified by gender and smoking status (1-10 cigarettes per day for light smokers or >10 cigarettes per day for moderate to heavy smokers). The primary outcome was a 7-day point prevalence of smoking cessation as measured by salivary cotinine at week 26. The secondary outcome was smoking abstinence for 7 days at week 12, with subgroup analyses for light smokers (1-10 cigarettes/day) and moderate to heavy smokers (>10 cigarettes/day).

The experiment was completed by 441 (88%) of the 500 individuals who were randomised and completed the baseline visit (mean age, 52 years; 262 [52%] women; 260 [52%] light smokes; 429 [86%] menthol users). Participants receiving varenicline were considerably more likely than those receiving placebo to be abstinent at week 26 (15.7% vs 6.5%; difference, 9.2% [95% CI, 3.8% -14.5%]; odds ratio [OR], 2.7 [95% CI, 1.4-5.1]; P=.002). At the conclusion of treatment week 12, the varenicline group had higher abstinence than the placebo group (18.7% vs 7.0%; difference, 11.7% [95% CI, 6.0% -17.7%]; OR, 3.0 [95% CI, 1.7-5.6]; P<.001). Smoking abstinence was significantly higher in individuals receiving varenicline compared to placebo at week 12 in light smokers (22.1% vs 8.5% ; difference, 13.6% [95% CI, 5.2% -22.0%]; OR, 3.0 [95% CI, 1.4-6.7]; P=.004) & moderate to heavy smokers (15.1% vs 5.3% ; difference, 9.8% [95% CI, 2.4% -17.2%]; OR, 3.1 [95% CI, 1.1-8.6]; P=.02), with no significant smoking level × treatment interaction (P=.96). Medication side effects were mainly equivalent across treatment groups, with nausea occurring more often in the varenicline group (163 of 293 [55.6%]) than in the placebo group (90 of 196 [45.9%]).

When compared to counselling and placebo, varenicline coupled to counselling resulted in a statistically significant improvement in rates of 7-day point prevalence smoking cessation at week 26 among African American adults who are daily smokers. The findings supported the use of varenicline in conjunction with counselling for tobacco use therapy among African American adults who smoke on a regular basis.