The lack of clinical studies on the use of Cytisine in the treatment of the cessation of smoking, the need to find effective therapeutic alternatives and the opportunity to reduce costs related to the complications of cigarette smoking, represent the main reasons that led to the design of this study.

The study is observational, retrospective and monocentric, and aims to evaluate patients who performed an initial pneumological examination at the Anti-Smoking Center of the National Institute Regina Elena tumors due to smoking cessation in the reference period. To such patients, affected of moderate or severe tobacco use disorder, drug therapy was prescribed with Cytisine 1.5 mg, with the aim of evaluating treatment adherence, efficacy and tolerability of Cytisine as monotherapy in the treatment of moderate or moderate tobacco use disorder serious. Responding patients will be taken into consideration for the study consecutively to the criteria established and pertaining to the Anti-Smoking Center of the National Cancer Institute Regina Elena in the period between 02/01/2023 and 11/30/2023 on first and subsequent visits controls.

Inclusion Criteria:

• patients aged > 18 years;
• patients suffering from moderate or severe tobacco use disorder;
• prescription of pharmacological therapy with Cytisine;
• patients returned to the 1st check-up on schedule;

Exclusion Criteria:

• Patients with contraindications to taking Cytisine and partial receptor agonists nicotinic cholinergics;
• Patients undergoing pharmacological or physical treatment for neoplastic pathology;
• Pregnant or breastfeeding women;
• Patients for whom specific information for objective assessments is not available;

Patients who have referred to the Anti-smoking Center of the IRE, National Cancer Institute "Regina Elena", and that meet the following criteria.