Discussion
retention of skills acquired, deterioration of skills
RECRUITMENT
We found that training with intervals of 1–2 days was not superior to intervals of 6–8 days in a proficiency-based laparoscopy simulator training program and that the two training schedules gave comparable results. Previous studies have shown that laparoscopic skills are acquired more efficiently in a distributed manner compared with massed practice [In contrast, a study conducted by Spruit et al. showed that spacing laparoscopic training over three consecutive days or weeks was superior to massed training. Even when the massed training contained breaks, breaks with sleep opportunities between sessions enhanced the performance compared to training with shorter breaks and massed training [Other studies show that surgical training is most efficient when scheduled across multiple shorter time intervals, preferably with several non-training days between training sessions [Our findings indicate that the most important issue in distributed practice is that there is at least one night of sleep between training sessions. This means that training programs should accommodate this, but also be flexible to fit with the work schedule of the surgical trainees. Our findings are also relevant for the organization of time-limited skills courses, which typically use massed practice on one or more days. If possible, training should be spread out over several days in shorter sessions, instead of doing it all on the same day, as this is more efficient for skills acquisition and reduces the risk of overload as earlier studies show [The distribution of training did not impact the amount of instructor feedback needed in the intervention and during the retention test. This is in line with our main findings that the training schedules did not influence the effectiveness of the training. That there was no difference in the need for instructor feedback supports that there is a limited deterioration of skills during intervals of up to 8 days.A strength of our trial was that we used a proficiency-based design over a time- or repetition-based training, which only focuses on the initial part of the learning curve. Additionally, our intervention was structured similarly to an actual simulation-based training program, meaning our findings can easily be applied to training programs. With the power of 90%, recruitment of more participants would not change the result of our study.It is a limitation that we only compared two training schedules, and had we included an additional group with an even longer interval between sessions we could theoretically have gotten different results. There is also a small risk of bias due to the 2-week interval where the retention test could be done and some could have practiced in the beginning and the end of the interval. However, a study by Bjerrum et al. found that there was still significant retention of skills acquired after proficiency-based laparoscopy simulator training after a period of 6 months without training, showing retention of skills over long periods of time, making this less likely [Furthermore, neither the investigators nor the participants were blinded to the intervention; we used medical students as participants and not doctors who are the actual target group of the laparoscopic training program, but the medical students were novices in laparoscopy similar to new residents and we believe the findings can be applied to this group. Finally, we did not examine transfer to a clinical setting: therefore, we cannot conclude anything about the impact of training intervals on actual clinical performance.In conclusion, we did not find any benefit of shorter intervals compared with longer intervals between training sessions in a proficiency-based laparoscopy simulator training program.