The educational value of using cumulative sum charts.

Various workplace-based assessment tools are available, but none have been shown to improve performance in procedural skills. This study aimed to assess the impact of using one such tool, cumulative sum charts, on procedural skill ability. A single-blind randomised controlled trial was conducted on 82 final year medical students. Control group students received the usual teaching; in addition to this, intervention group students were provided with cumulative sum charts to log their cannulation attempts over a 7-month period. At the end of the year, students from both groups undertook a validated test of automaticity of cannulation skill. Students in the intervention group obtained median (IQR [range]) scores of 68.2 (60.5-74.3 [42.7-81.1]) vs 62.2 (52.2-68.8 [40.7-80.5]) for the control group (p = 0.013). The effect size was moderate (Cohen's d = 0.608). This study therefore provides support for the hypothesis that use of cumulative sum charts improves performance when learning procedural skills.