We found that proficiency was achieved by 100% of the LC group at the fourth session (LC4). We found no differences when comparing the LC4 and the GF group’s OSATS and DOPS scores. Both the LC and GF groups had significantly superior OSATS results compared to the BG group; there were no differences in the DOPS scores between the three groups.
The main strength of this work is that we evaluated the students’ performance by analyzing their learning curve. This is a very important strength of this study, since one of the main confounding biases in previous educational studies has been the focus on evaluating the outcome of education after conducting just a “point in time” training, exemplified by the boot camp training. Another strength of our study is the high quality of the study design. Specifically, we believe that the experimental interventions, the blinded experts who reviewed the videos, and the validated scales used to measure the outcomes give strong internal validity to our work.
One of the main limitations of this study is the absence of randomization. This problem was considered during the design and planning of the study; however, we decided to go with a quasi-experimental design because we were not able to randomize the gastroenterology fellows nor the medical students as they were recruited one by one during different periods.
Another limitation is that the simulated model made in our institution does not contain echogenic materials; thus, the paracentesis was performed using classic anatomical repairs. However, this is compatible with local reality, where only a minority of punctures are ultrasound-guided. We also believe that the absence of paracentesis training on a real patient and the evaluation of the learning curve for this procedure could be an additional limitation; nevertheless, it seems unethical to train medical students on real patients due to the strong evidence supporting the use of simulation as a method of learning technical skills. Moreover, as we noted in our results, even clinical experience of 20 or more procedures without previous standardized training does not guarantee proficiency [6, 12].
Knowing and understanding the learning curves of medical and surgical procedures is essential to designing effective training programs and defining the minimum competencies for medical education [17, 25]. Therefore, the purpose of this study was to determine the learning curve in acquiring the technical skills to perform paracentesis in a simulated model and compare it with the performance of students trained by the widely accepted boot camp method. We also compared both groups with gastroenterology fellows, who are used to executing this procedure during their daily clinical practice.
Our undergraduate medical students trained through the LC program achieved a level of procedural proficiency comparable to the performance of more experienced professionals, that is, the gastroenterology fellows, who have four to five years of postgraduate training. Conversely, the students trained through the boot camp method (BC) had statistically significant worse results in terms of the skills they acquired, and 34% did not reach the required proficiency level at the end of their training. Moreover, one of the gastroenterology fellows did not meet the proficiency criteria in his performance, reflecting the importance of standardized training.
The results of this study allow us to claim that a paracentesis simulation-based training program requires at least three to four practical sessions for students to achieve proficiency. Students acquire technical skills progressively and in a standardized methodological sequence, whereas in the boot camp method, they are asked to recall procedural steps seen in a video just a few minutes previously [6]. Thus, we recommend moving from the one-day boot camp method in SBML to short, successive training sessions with deliberate practice on a simulated model, which results in progressive learning [10, 13].
Although the overall cost per student of the LC intervention is higher, one-third of the students in the BC group had to repeat the workshop, which was not factored into the cost analysis. Regardless of the learning methodology, the highest cost was related to the teaching time (Table 5).
In future studies, alternatives to optimize teaching and feedback can be explored, such as tele-mentoring. Quezada et al. used this methodology to teach advanced laparoscopic surgical skills through a mobile app, with remote feedback provided by expert tutors [26]. This novel method could optimize the teaching time and has been proved as effective as in-person instruction [26]. Also, current studies on simulation-based programs and medical/surgical skills still focus primarily on levels 1 and 2 of the Kirkpatrick model for learning evaluation and educational impact [4, 15, 27, 28]. More research is needed on levels 3 (transfer of skills to real patients) and 4 (costs and service quality).
In conclusion, this study outlines a learning curve for the paracentesis procedure in a simulated model and demonstrates that a SBML program based on that learning curve improves technical skills significantly in medical students. Also, the performance of the students trained with this method was comparable with that of gastroenterology fellows with much more clinical experience.