Background: To analyze the effectiveness of two group interventions for smoking cessa-tion (with support from the app) conducted by primary care nurses. Methods: A multi-center randomized controlled clinical trial occurred across eight Health Centres in the Murcia Region from 2018 to 2019. It involved daily smokers aged 18 and older who wanted to quit, had internet access, and spoke Spanish. Pregnant women, polydrug users, and individuals with psychiatric disorders were excluded from participation. Participants were randomly divided into two groups: one attending a single 4-hour Workshop, and the other attending a Course consisting of four 2-hour sessions. The analysis of smoking abstinence was performed using SPSS V22, with intragroup differences assessed through the chi-square test.

The project was conceived as a randomised, multicentre clinical trial aimed at comparing the efficacy of two group-based intervention modalities for smoking cessation, both led by primary care nurses and supplemented by using the S'Acabó mobile application. The study was conducted in health centres across the Region of Murcia between 2018 and 2019, with participants being followed up for one year. The target population comprised adult smokers who expressed a desire to quit smoking, had internet access, and did not present with severe psychiatric disorders or concurrent substance use.

Allocation to the intervention groups was performed randomly: one group participated in a single four-hour workshop, whilst the other attended a course consisting of four weekly sessions, each lasting two hours. Both modalities incorporated cognitive-behavioural techniques and participatory methodologies to enhance individual motivation and group learning through the exchange of experiences and peer support.

The nurses responsible for delivering the interventions received specific training in smoking cessation, group education, and the management of group dynamics, thereby ensuring the standardisation and quality of the process. The study protocol included the systematic collection of sociodemographic, clinical, and tobacco consumption data, the assessment of psychological variables and the utilisation of complementary resources, including the mobile application. Follow-up of participants was conducted through face-to-face visits and telephone contacts at various points throughout the year, enabling the monitoring of the smoking cessation process and adherence to the proposed strategies. Statistical analysis of the data was carried out by international methodological standards, employing validated tools and ensuring the robustness and reliability of the results obtained.

Inclusion criteria:

• Daily smokers aged over 18 years.
• Smoking history of at least one year.
• Intention to quit smoking within one month.
• Ability to communicate in Spanish.
• Ownership of a mobile device with internet access.

Exclusion criteria:

• Consumption of other drugs (excluding cannabis).
• Participation in smoking cessation programmes within the past year.
• Diagnosis of an acute psychotic disorder.
• Adolescents.
• Pregnant women.