This study combined two approaches widely advocated for improving safety: teamwork training and involving patients in safety efforts. In response to prior research on safety problems in outpatient chemotherapy suites, the investigators implemented a teamwork training intervention with the assistance of patient volunteers. Based on safety principles such as situational awareness and closed-loop communication, the intervention focused on encouraging patients to ask specific questions regarding their care. Patients who were aware of the program reported that they changed their behaviors as a result. This is one of the first studies to report on engaging patients in a teamwork intervention.