Purpose To develop a patient safety curriculum and evaluate its impact on medical students' safety knowledge, self-efficacy and system thinking.

Methods This study reports on curriculum development and evaluation of a 3-day, clinically oriented patient safety intersession that was implemented at the Johns Hopkins School of Medicine in January 2011. Using simulation, skills demonstrations, small group exercises and case studies, this intersession focuses on improving students' teamwork and communication skills and system-based thinking while teaching on the causes of preventable harm and evidence-based strategies for harm prevention. One hundred and twenty students participated in this intersession as part of their required second year curriculum. A pre–post assessment of students' safety knowledge, self-efficacy in safety skills and system-based thinking was conducted. Student satisfaction data were also collected.

Results Students' safety knowledge scores significantly improved (mean +19% points; 95% CI 17.0 to 21.6; p<0.01). Composite system thinking scores increased from a mean pre-intersession score of 60.1 to a post-intersession score of 67.6 (p<0.01). Students had statistically significant increases in self-efficacy for all taught communication and safety skills. Participant satisfaction with the intersession was high.

Conclusions The patient safety intersession resulted in increased knowledge, system-based thinking, and self-efficacy scores among students. Similar intersessions can be implemented at medical, nursing, pharmacy and other allied health schools separately or jointly as part of required school curricula. Further study of the long-term impact of such education on knowledge, skills, attitudes and behaviours of students is warranted.