BACKGROUND: Early in medical education, physicians must develop competencies needed for tobacco dependence treatment.

OBJECTIVE: To assess the effect of a multi-modal tobacco dependence treatment curriculum on medical students' counseling skills.

DESIGN: A group-randomized controlled trial (2010-2014) included ten U.S. medical schools that were randomized to receive either multi-modal tobacco treatment education (MME) or traditional tobacco treatment education (TE).

SETTING/PARTICIPANTS: Students from the classes of 2012 and 2014 at ten medical schools participated. Students from the class of 2012 (N = 1345) completed objective structured clinical examinations (OSCEs), and 50 % (N = 660) were randomly selected for pre-intervention evaluation. A total of 72.9 % of eligible students (N = 1096) from the class of 2014 completed an OSCE and 69.7 % (N = 1047) completed pre and post surveys.

INTERVENTIONS: The MME included a Web-based course, a role-play classroom demonstration, and a clerkship booster session. Clerkship preceptors in MME schools participated in an academic detailing module and were encouraged to be role models for third-year students.

MEASUREMENTS: The primary outcome was student tobacco treatment skills using the 5As measured by an objective structured clinical examination (OSCE) scored on a 33-item behavior checklist. Secondary outcomes were student self-reported skills for performing 5As and pharmacotherapy counseling.

RESULTS: Although the difference was not statistically significant, MME students completed more tobacco counseling behaviors on the OSCE checklist (mean 8.7 [SE 0.6] vs. mean 8.0 [SE 0.6], p = 0.52) than TE students. Several of the individual Assist and Arrange items were significantly more likely to have been completed by MME students, including suggesting behavioral strategies (11.8 % vs. 4.5 %, p < 0.001) and providing information regarding quitline (21.0 % vs. 3.8 %, p < 0.001). MME students reported higher self-efficacy for Assist, Arrange, and Pharmacotherapy counseling items (ps < /=0.05).

LIMITATIONS: Inclusion of only ten schools limits generalizability.

CONCLUSIONS: Subsequent interventions should incorporate lessons learned from this first randomized controlled trial of a multi-modal longitudinal tobacco treatment curriculum in multiple U.S. medical schools.

NIH Trial Registry Number: NCT01905618.