Cytisine versus varenicline for smoking cessation in New Zealand indigenous Māori: A randomized controlled trial.

AIM To determine whether cytisine was at least as effective as varenicline in supporting smoking abstinence for ≥ 6 months in New Zealand indigenous Māori or whānau (extended-family) of Māori, given the high smoking prevalence in this population. DESIGN Pragmatic, open-label, randomised, community-based non-inferiority trial. SETTING Bay of Plenty, Tokoroa, and Lakes District Health Board regions of New Zealand. PARTICIPANTS Adult daily smokers who identified as Māori or whānau of Māori, were motivated to quit in the next 2 weeks, were aged ≥18 years, and were eligible for subsidised varenicline. Recruitment used multi-media advertising. INTERVENTIONS 679 people were randomly assigned (1:1) to receive a prescription for 12-weeks of cytisine or varenicline, plus low-intensity cessation behavioural support from the prescribing doctor and community stop-smoking services or a research assistant. Day five of treatment was the designated quit date. MEASUREMENTS The primary outcome was carbon-monoxide verified continuous abstinence at 6 months, analysed as intention to treat (with multiple imputation for missing data). Secondary outcomes measured at 1, 3, 6 and 12 months post-quit date included: self-reported continuous abstinence, 7-day point prevalence abstinence, cigarettes per day, time to (re)lapse, adverse events, treatment adherence/compliance and acceptability, nicotine withdrawal/urge to smoke, and healthcare utilisation/health-related quality of life. FINDINGS Verified continuous abstinence rates at 6 months post-quit date were 12.1% (41 of 337) for cytisine vs 7.9% (27 of 342) for varenicline (risk difference 4.29%, 95% confidence interval [CI] -0.22 to 8.79; relative risk 1.55; 95% CI 0.97 to 2.46). Sensitivity analyses confirmed the findings were robust. Self-reported adverse events over 6 months occurred significantly more frequently in the varenicline group (cytisine: 313 events in 111 participants; varenicline: 509 events in 138 participants, incidence rate ratio 0.56, 95% CI 0.49 to 0.65, p<0.001) compared with the cytisine group. Common adverse events were headache, nausea, and difficulty sleeping. CONCLUSION A randomised controlled trial found that cytisine was at least as effective as varenicline at supporting smoking abstinence in New Zealand indigenous Māori or whānau (extended-family) of Māori, with significantly fewer adverse events.