Factors influencing sustainable efficacy of smoking cessation treatment with varenicline beyond nine months

Pharmacological therapies play an important role in the success of interventions for smoking cessation; however, long-term follow-up studies with analysis of influencing factors are scarce. We examined the sustainable effects of smoking cessation therapy with varenicline, beyond nine months as well as the factors influencing effectiveness. Our sample consisted of 193 patients (126 men [68.2%], 67 women [31.8%], aged 26 to 85 years) who underwent varenicline therapy at the Nagoya University Hospital between January 2009 and October 2013. We examined their clinical records and also conducted a mail survey and evaluated success rates of smoking cessation therapy beyond nine months. Overall, 95.8% (185/193) of the patients had at least one complication. The response rate of questionnaires at the end of smoking cessation was 61.6% (119/193). The smoking cessation rate continued to decline for one year and leveled off afterwards. Smoking cessation rates tended to correlate with an increasing number of outpatient visits. Logistic regression analysis showed that two factors, young age and high Beck Depression Inventory-II (BDI-II) scores, were inversely correlated with success rates of smoking cessation. From the results of this study, aggressive intervention would needed for younger patients or patients with higher BDI-II scores.