• Background:** Brief tobacco intervention (BTI) is a key component in addressing the tobacco pandemic. The WHO recommends incorporating specific training on tobacco dependence and cessation into the curricula of health professionals. In studies published on smoking cessation training for nursing students, debriefing is used as a key tool.
• Objectives:** To determine the effectiveness of debriefing following an objective evaluation of BTI training in nursing students and to assess its impact at 3 and 9 months.
• Design:** Randomized controlled clinical trial with block randomization to evaluate the debriefing intervention versus no debriefing, with follow-up measurements taken five times over a period of 9 months.
• Participants:** The study was conducted with second-year nursing students at the University of Murcia, Spain, during the 2021-2023 academic years.
• Methods:** Both the experimental group (EG) and the control group (CG) received BTI training according to the 5 As and 5 Rs model in a brief 2.5-hour format in groups of 13-16 students. The data collection protocol was similar in both the EG and CG, with 5 measurements taken, always following the viewing of the 3 problem-solving videos and evaluating learning through the BTI-St®. The baseline measurement was taken before the BTI training (T0), followed by another measurement after students in both groups received BTI training in primary care (T1). Subsequently, in the experimental group, an expert instructor conducted a structured debriefing of approximately 10-15 minutes for each clinical scenario, while the control group received no additional intervention. At the end of the first day, all participants viewed the videos and completed the tool again (T2). At three and nine months, students viewed the videos and measurements were taken at T3 and T4, respectively. A two-factor repeated measures ANOVA was used to analyze intra-subject and inter-subject differences.

**Method of Measurement**

To assess changes in learning related to brief tobacco intervention (BTI) among nursing students, the Brief Tobacco Intervention BTI-St© tool was used, employing the standardized patient videos previously described. This instrument is based on a criterion-referenced test or competency test model, allowing for an objective evaluation of student performance in BTI and the identification of learning deficiencies. It is presented as an algorithm comprising 23 dichotomous items organized according to the 5As and 5Rs model, and it has demonstrated adequate validity and reliability (Ramos-Morcillo et al., 2022). Students are required to watch a video-recorded clinical scenario and indicate whether the criteria for brief smoking cessation intervention are met. Responses are scored against the gold standard defined in the validation of the scenarios, with item scores ranging from 0 (incorrect) to 1 (correct). The total maximum score for the presented scenarios ranges from 0 to 1 point if the student correctly answers all the items.

Inclusion Criteria:

• The inclusion criteria were being enrolled in the second-year course "Foundations of Community Nursing," where BTI training is provided, and agreeing to participate in the study.

Exclusion Criteria:

• Nothing