Abstinence and relapse among smokers who use varenicline in a quit attempt-a pooled analysis of randomized controlled trials.
Level 1 - systematic review of randomized trials
Meta-analysis of randomized controlled trials
PubMed 25846123 · doi:10.1111/add.12941
What was done
A random-effects meta-analysis of data from 19 randomized controlled trials identified from a 2012 Cochrane review evaluated abstinence and relapse patterns in adult daily smokers receiving varenicline versus placebo. Included trials had follow-up at 6 or 12 months and at least three follow-ups in the first month. Outcomes evaluated were biochemically verified point-prevalence abstinence at weeks 2, 3, 4, 12, 24, and 52, and continuous abstinence at weeks 9–12, 9–24, and 9–52.
What was found
Point-prevalence abstinence increased by 22 percentage points in varenicline-treated participants from week 2 (32%, 95% CI = 25–40%) to week 12 (54%, 95% CI = 48–61%), compared with an 8 percentage point increase in placebo-treated participants (16%, 95% CI = 11–21% to 24%, 95% CI = 17–33%). Relapse from weeks 9–12 to week 52 was 55% for varenicline (abstinence fell from 49%, 95% CI = 45–53% to 22%, 95% CI = 19–25%) and 53% for placebo (abstinence fell from 17%, 95% CI = 13–25% to 8%, 95% CI = 6–12%).
Why it matters
The findings show that varenicline enhances cessation partly by recruiting smokers into abstinence even if they fail to stop on their initial quit date, while demonstrating that post-treatment relapse rates are not elevated compared to placebo.
Limits
The total number of individual participants across trials is not stated in the abstract. Inclusion was restricted to trials with frequent early follow-ups identified from a single 2012 review, and safety outcomes, adverse effects, and variations in co-interventions or behavioral support are not described.
Cited by
- supports Varenicline yields a 20% to 30% abstinence rate for smoking cessation.