Association between early treatment response and long-term smoking cessation: A real-world retrospective cohort study of cytisine treatment

INTRODUCTIONCytisine is an effective and cost-efficient pharmacotherapy for smoking cessation; however, real-world evidence regarding treatment outcomes within structured behavioral programs remains limited.This study aimed to evaluate short-and mid-term smoking cessation outcomes following cytisine treatment and to identify factors associated with treatment success, with particular emphasis on early treatment response as a marker of long-term abstinence.METHODS This retrospective cohort study included 364 consecutive adult smokers who initiated cytisine treatment within a structured smoking cessation program at a tertiary outpatient clinic between April 2023 and February 2025.Smoking abstinence was assessed at 1 and 6 months through outpatient visits and structured telephone interviews recorded in the Turkish National Smoking Cessation Registry System (TUBATIS).Baseline demographic characteristics, nicotine dependence assessed using the Fagerström test for nicotine dependence (FTND), cumulative smoking exposure, and previous smoking cessation treatment were evaluated.Multivariable logistic regression, interaction analyses, receiver operating characteristic (ROC) curve analyses, and Kaplan-Meier survival analyses were performed.RESULTS Smoking abstinence was achieved by 114 patients (31.3%) at 1 month and 67 (18.4%) at 6 months.Early responders had substantially higher 6-month abstinence rates than early non-responders (49.1% vs 4.4%), and early treatment response was strongly associated with sustained abstinence after multivariable adjustment (AOR=9.8;95% CI: 4.7-20.5;p<0.001).Lower cumulative smoking exposure (≤20 pack-years) was independently associated with early abstinence (AOR=3.55;95% CI: 1.99-6.36;p<0.001), whereas sex, nicotine dependence, age, and previous cessation treatment were not independently associated with 1-month abstinence.A significant interaction between nicotine dependence and smoking exposure was observed (p=0.028).A prediction model incorporating early treatment response demonstrated better discrimination for 6-month abstinence than a baseline clinical model (AUC: 0.82 vs 0.68).CONCLUSIONS Early treatment response was strongly associated with sustained smoking abstinence and may represent a clinically useful time point for treatment reassessment.Baseline nicotine dependence and cumulative smoking exposure were also associated with cessation outcomes, supporting individualized risk assessment and follow-up.