1. A double-blinded, randomized controlled trial found that varenicline significantly improved the rate of abstinence from smoking in African American patients up to at least 6 months.
2. The primary adverse event associated with varenicline was nausea.
Level of Evidence Rating: 1 (Excellent)
Study Rundown: Cigarette smoking is a common habit associated with detrimental health consequences; this is especially true amongst African AmericanAfrican American adults, who have higher documented morbidity and mortality from smoking than White adults. Furthermore, African American smokers are considerably underrepresented in studies of smoking cessation interventions. Varenicline (“Champix”) is a partial nicotinic receptor agonist which is well-established as an effective smoking cessation tool in some populations. The Kick It at Swope (KIS-IV) trial series aimed to better understand strategies for smoking cessation amongst African American smokers specifically. 500 participants were randomized in total, with 300 receiving varenicline and 200 receiving placebo. Participants randomized to the varenicline group were significantly more likely to have been abstinent at both 12 weeks and at 26 weeks follow up as evidenced by a biochemical measure of 7-day point smoking prevalence in saliva samples. The success of varenicline in assisting with smoking cessation was more pronounced in light smokers than in moderate or heavy smokers. Rates of self-reported adverse events were similar amongst the two groups, although nausea was more common in varenicline users. This randomized controlled trial demonstrated that varenicline may be an effective smoking cessation intervention amongst African American daily smokers. These findings are logical, given the established role of varenicline as a helpful smoking cessation adjunct in the population at large. This work is important in establishing evidence for an intervention which can, eventually, improve health outcomes amongst a group who have been historically excluded from large trials. A primary limitation of this work is the stringent eligibility criteria which reduces the external validity of these findings. However, the findings are strengthened by the large sample size and randomized trial design used.
In-Depth [randomized controlled trial]: A double-blinded, randomized controlled trial was conducted at the University of Kansas Medical Center. Eligible participants were self-identified African American individuals over the age of 18 who had smoked at least 1 cigarette in 25 of the past 30 days and were motivated to quit. Importantly, patients who had previously tried smoking cessation medications (i.e., nicotine replacement therapy, bupropion or varenicline) were excluded, as were patients with concurrent mental health disorders. Included participants were randomized in a 3:2 fashion to either varenicline or placebo. The trial involved undergoing 12 weeks of medical therapy (with varenicline or placebo) as well as 6 counseling sessions which consisted of cognitive behavioral therapy and teaching on the importance of medication adherence. Participants were asked to stop smoking on day 8 of medical therapy. Participants were remunerated a small amount of cash for attending study visits. The primary outcome was biochemical evidence of smoking within 7 days (markers in saliva & urine samples) measured at 26 weeks. This was achieved by 15.7% of the varenicline patients and 6.5% of the placebo patients; the odds ratio for achieving the primary outcome in the varenicline versus control group was 2.6 (95% confidence interval 1.4-5.1). This finding was robust to sensitivity analyses. The difference in abstinence rates was also statistically significant at 12 weeks, with 18.7% of the varenicline group and 7.0% of the placebo group abstaining at this time (odds ratio 3.0, 1.7-5.6). The odds ratio for achieving the primary outcome in the varenicline versus placebo groups after 12 weeks was 3.0 (1.4-6.7) amongst those considered light smokers and was 3.1 (1.1-8.6) amongst moderate or heavy smokers. 22.1% of light smokers were abstinent at 12 weeks while 15.1% of moderate/heavy smokers were. No serious adverse events were reported in either group, and the side effects experienced were quite similar other than nausea (endorsed by 55.6% of varenicline users and 45.9% of placebo participants) at 16 weeks.
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