Markus Krautter, Ronja Dittrich, Annette Safi, Justine Krautter, Imad Maatouk, Andreas Moeltner, Wolfgang Herzog, Christoph Nikendei

Although Peyton's four-step approach is a widely used method for skills-lab training in undergraduate medical education and has been shown to be more effective than standard instruction, it is unclear whether its superiority can be attributed to a specific single step. We conducted a randomized controlled trial to investigate the differential learning outcomes of the separate steps of Peyton's four-step approach. Volunteer medical students were randomly assigned to four different groups. Step-1 group received Peyton's Step 1, Step-2 group received Peyton's Steps 1 and 2, Step-3 group received Peyton's Steps 1, 2, and 3, and Step-3mod group received Peyton's Steps 1 and 2, followed by a repetition of Step 2. Following the training, the first independent performance of a central venous catheter (CVC) insertion using a manikin was video-recorded and scored by independent video assessors using binary checklists. The day after the training, memory performance during delayed recall was assessed with an incidental free recall test. A total of 97 participants agreed to participate in the trial. There were no statistically significant group differences with regard to age, sex, completed education in a medical profession, completed medical clerkships, preliminary memory tests, or self-efficacy ratings. Regarding checklist ratings, Step-2 group showed a superior first independent performance of CVC placement compared to Step-1 group (P<0.001), and Step-3 group showed a superior performance to Step-2 group (P<0.009), while Step-2 group and Step-3mod group did not differ (P=0.055). The findings were similar in the incidental free recall test. Our study identified Peyton's Step 3 as being the most crucial part within Peyton's four-step approach, contributing significantly more to learning success than the previous steps and reaching beyond the benefit of a mere repetition of skills demonstration.