Refreshing medical students’ intravenous-cannulation skills: a blinded observer three-arm randomised comparison of mental imagery, part-task trainer simulation and written instructions

INTRODUCTION: Intravenous cannulation is a core competence in medicine, but is considered challenging to learn. This study investigates the effectiveness of three educational strategies used to refresh the intravenous cannulation skills of first-year medical students: mental imagery, part-task trainer simulation and written instructions. MATERIALS AND METHODS: In this single-centre randomised controlled trial, first-year medical students were assigned to one of three different refresher tutorials on intravenous cannulation. Six months after their compulsory 4 hour instructor-led intravenous-cannulation course, each student was randomised to a 6 min self-learning tutorial: a mental imagery audioguide session, hands-on intravenous cannulation on a part-task trainer or reading written instructions. Immediately after the refresher tutorials, trained evaluators who were blinded to the randomised group assessed the students’ performance. Each evaluator completed a 15-item standardised checklist in an Objective Structured Clinical Examination (OSCE) station for intravenous cannulation. We performed a descriptive analysis of the data and a one-way analysis of variance. Additionally, we investigated the influence of previous intravenous cannulation experience on the total OSCE score. RESULTS AND DISCUSSION: On analysing the 309 students’ results, we did not find differences in the total rating of the performance (in percentage) between the three groups at the OSCE station (mental imagery group: 72.0%±17.9%; part-task trainer group: 74.4%±15.6%; written instructions group: 69.9%±16.6%, p=0.158). Multiple linear regression showed a small but statistically significant effect of students’ previous intravenous cannulation experience on OSCE performance. With the same outcome, written instructions and mental imagery had a better return on effort, compared with resource-intensive hands-on training with part-task trainers. CONCLUSION: A single, short refresher seems to have a limited effect on intravenous-cannulation skills in first-year medical students. Less resource-intensive interventions, such as written instructions or mental imagery, are effective compared with hands-on part-task trainer simulation for refreshing this simple but important skill. TRIAL REGISTRATION NUMBER: AEARCTR-0008043.