Steven Andersen
MD, PhD
Instructional design
Publication Types:
Mastoidectomy training—is anatomical variation needed? A randomized, controlled trial on performance and skills transfer from Virtual Reality to a 3D-printed model
Am I doing this right? Structured self-assessment during simulation training of mastoidectomy improves cadaver dissection performance: a prospective educational study
Purpose: Temporal bone surgery requires excellent surgical skills and simulation-based training can aid novices’ skills acquisition. However, simulation-based training is challenged by early stagnation of the learning after relatively few performances. Structured self-assessment during practice might enhance learning by inducing reflection and engagement in the learning task. In this study, structured self-assessment was introduced during virtual reality (VR) simulation of mastoidectomy to investigate the effects on subsequent performance during cadaveric dissection.
Methods: This was a prospective educational study with comparison with historical controls (reference cohort). At a temporal bone dissection course, eighteen participants performed structured self-assessment during three hours of VR simulation training of mastoidectomy before proceeding to cadaver dissection/surgery (intervention cohort). At a previous course, eighteen participants received similar VR simulation training but without the structured self-assessment (reference cohort). Final products from VR simulation and cadaveric dissection were video-recorded and assessed by two blinded raters using a 19-point modified Welling Scale.
Results: The intervention cohort completed fewer procedures (average 4.2) during VR simulation training than the reference cohort (average 5.7). Nevertheless, the intervention cohort achieved a significantly higher average dissection score both in VR simulation (11.1 points, 95% CI [10.6–11.5]) and subsequent cadaveric dissection (11.8 points, 95% CI [10.7–12.8]) compared with the reference cohort who scored 9.1 points (95% CI [8.7–9.5]) during VR simulation and 5.8 points (95% CI [4.8–6.8]) during cadaveric dissection.
Conclusion: Structured self-assessment is a valuable learning support during self-directed VR simulation training of mastoidectomy and the positive effect on performance transfers to subsequent cadaveric dissection performance.
The effect of simulator-integrated tutoring for guidance in virtual reality simulation training
INTRODUCTION: Simulation-integrated tutoring in virtual reality (VR) simulation training by green-lighting is a common learning support in simulation-based temporal bone surgical training. However, tutoring overreliance can negatively affect learning. We therefore wanted to investigate the effects of simulator-integrated tutoring on performance and learning.
METHODS: A prospective, educational cohort study of a learning intervention (simulator-integrated tutoring) during repeated and distributed VR simulation training for directed, self-regulated learning of the mastoidectomy procedure. Two cohorts of novices (medical students) were recruited: 16 participants were trained using the intervention program (intermittent simulator-integrated tutoring) and 14 participants constituted a non-tutored reference cohort. Outcomes were final-product performance assessed by two blinded raters, and simulator-recorded metrics.
RESULTS: Simulator-integrated tutoring had a large and positive effect on the final-product performance while turned on (mean difference 3.8 points, p<0.0001). However, this did not translate to a better final-product performance in subsequent non-tutored procedures. The tutored cohort had a better metrics-based score, reflecting higher efficiency of drilling (mean difference 3.6 %, p=0.001). For the individual metrics, simulator-integrated tutoring had mixed effects both during procedures and on the tutored cohort in general (learning effect).
CONCLUSIONS: Simulator-integrated tutoring by green-lighting did not induce a better final-product performance but increased efficiency. The mixed effects on learning could be caused by tutoring overreliance, resulting from a lack of cognitive engagement when the tutor-function is on. Further learning strategies such as feedback should be explored to support novice learning and cognitive engagement.
Reliable assessment of surgical technical skills is dependent on context: an exploration of different variables using Generalizability theory
Purpose: Reliable assessment of surgical skills is vital for competency-based medical training. Several factors influence not only the reliability of judgements but also the number of observations needed for making judgments of competency that are both consistent and reproducible. The aim of this study was to explore the role of various conditions-through the analysis of data from large-scale, simulation-based assessments of surgical technical skills-by examining the effects of those conditions on reliability using Generalizability theory.
Method: Assessment data from large-scale, simulation-based temporal bone surgical training research studies in 2012-2018 were pooled, yielding collectively 3,574 assessments of 1,723 performances. The authors conducted generalizability analyses using an unbalanced random-effects design, and they performed decision studies to explore the effect of the different variables on projections of reliability.
Results: Overall, five observations were needed to achieve a Generalizability coefficient > 0.8. Several variables modified the projections of reliability: increased learner experience necessitated more observations (5 for medical students, 7 for residents, and 8 for experienced surgeons); the more complex cadaveric dissection required fewer observations than virtual reality simulation (2 vs. 5 observations); and increased fidelity simulation graphics reduced the number of observations needed from 7 to 4. The training structure (either massed or distributed practice) and simulator-integrated tutoring had little effect on reliability. Finally, more observations were needed during initial training when the learning curve was steepest (6 observations) compared with the plateau phase (4 observations).
Conclusions: Reliability in surgical skills assessment seems less stable than it is often reported to be. Training context and conditions influence reliability. The findings from this study highlight that medical educators should exercise caution when using a specific simulation-based assessment in other contexts.
Effects on cognitive load of tutoring in virtual reality simulation training
Aims: According to the guidance hypothesis, tutoring during technical skills training can result in tutoring over-reliance, reflected in a negative effect on performance when tutoring is discontinued. In this study, we wanted to explore if similar effects would be found for cognitive load.
Methods: Two cohorts of novice medical students were recruited for distributed virtual simulation training (five practice blocks of three procedures): 16 participants received intermittent simulator-integrated tutoring and 14 participants served as a reference cohort and did not receive simulator-integrated tutoring. Cognitive load during simulation was estimated using secondary task reaction time. Linear mixed models were used to account for repeated measurements.
Results: Overall, the tutored cohort had a significantly higher cognitive load than the reference cohort (mean difference = 7 %, p=0.006). Simulator-integrated tutoring did seem to lower cognitive load when active but also caused the tutored cohort to have a substantially higher cognitive load in subsequent performances where it was turned off (mean difference = 7 %, respectively, p<<0.001).
Conclusions: Concurrent feedback by simulator-integrated tutoring causes tutoring over-reliance and modifies cognitive load. This suggests that tutoring, in addition to degrading motor skills learning also affects the cognitive processes involved.
Understanding the effects of structured self-assessment in directed, self-regulated simulation-based training of mastoidectomy: a mixed methods study
OBJECTIVE: Self-directed training represents a challenge in simulation-based training as low cognitive effort can occur when learners overrate their own level of performance. This study aims to explore the mechanisms underlying the positive effects of a structured self-assessment intervention during simulation-based training of mastoidectomy.
METHODS: A prospective, educational cohort study of a novice training program consisting of directed, self-regulated learning with distributed practice (5×3 procedures) in a virtual reality temporal bone simulator. The intervention consisted of structured self-assessment after each procedure using a rating form supported by small videos. Semi-structured telephone interviews upon completion of training were conducted with 13 out of 15 participants. Interviews were analysed using directed content analysis and triangulated with quantitative data on secondary task reaction time for cognitive load estimation and participants’ self-assessment scores.
RESULTS: Six major themes were identified in the interviews: goal-directed behaviour, use of learning supports for scaffolding of the training, cognitive engagement, motivation from self-assessment, self-assessment bias, and feedback on self-assessment (validation). Participants seemed to self-regulate their learning by forming individual sub-goals and strategies within the overall goal of the procedure. They scaffolded their learning through the available learning supports. Finally, structured self-assessment was reported to increase the participants’ cognitive engagement, which was further supported by a quantitative increase in cognitive load.
CONCLUSIONS: Structured self-assessment in simulation-based surgical training of mastoidectomy seems to promote cognitive engagement and motivation in the learning task and to facilitate self-regulated learning.
The effect of structured self-assessment in virtual reality simulation training of mastoidectomy.
PURPOSE: Virtual reality (VR) simulation surgical skills training is well established, but self-directed practice is often associated with a learning curve plateau. In this study, we investigate the effects of structured self-assessment as a means to improve performance in mastoidectomy training.
METHODS: The study was a prospective, educational study. Two cohorts of novices (medical students) were recruited for practice of anatomical mastoidectomy in a training program with five distributed training blocks. Fifteen participants performed structured self-assessment after each procedure (intervention cohort). A reference cohort of another 14 participants served as controls. Performances were assessed by two blinded raters using a modified Welling Scale and simulator-recorded metrics.
RESULTS: The self-assessment cohort performed superiorly to the reference cohort (mean difference of final product score 0.87 points, p = 0.001) and substantially reduced the number of repetitions needed. The self-assessment cohort also had more passing performances for the combined metrics-based score reflecting increased efficiency. Finally, the self-assessment cohort made fewer collisions compared with the reference cohort especially with the chorda tympani, the facial nerve, the incus, and the malleus.
CONCLUSIONS: VR simulation training of surgical skills benefits from having learners perform structured self-assessment following each procedure as this increases performance, accelerates the learning curve thereby reducing time needed for training, and induces a safer performance with fewer collisions with critical structures. Structured self-assessment was in itself not sufficient to counter the learning curve plateau and for continued skills development additional supports for deliberate practice are needed.
Decentralized Virtual Reality Training of Mastoidectomy Improves Cadaver Dissection Performance: A Prospective, Controlled Cohort Study
OBJECTIVE: Virtual reality (VR) simulation training can improve temporal bone (TB) cadaver dissection skills and distributed, self-regulated practice is optimal for skills consolidation. Decentralized training (DT) at the trainees’ own department or home offers more convenient access compared with centralized VR simulation training where the simulators are localized at one facility. The effect of DT in TB surgical training is unknown. We investigated the effect of decentralized VR simulation training of TB surgery on subsequent cadaver dissection performance.
STUDY DESIGN: Prospective, controlled cohort study.
SETTING: Otorhinolaryngology (ORL) teaching hospitals and the Danish national TB course.
PARTICIPANTS: Thirty-eight ORL residents: 20 in the intervention cohort (decentralized training) and 18 in the control cohort (standard training during course).
INTERVENTION: Three months of access to decentralized VR simulation training at the local ORL department or the trainee’s home. A freeware VR simulator (the visible ear simulator [VES]) was used, supplemented by a range of learning supports for directed, self-regulated learning.
MAIN OUTCOME MEASURE: Mastoidectomy final-product scores from the VR simulations and cadaver dissection were rated using a modified Welling Scale by blinded expert raters.
RESULTS: Participants in the intervention cohort trained decentrally a median of 3.5 hours and performed significantly better than the control cohort during VR simulation (p < 0.01), which importantly also transferred to a 76% higher performance score during subsequent cadaver training (mean scores: 8.8 versus 5.0 points; p < 0.001).
CONCLUSIONS: Decentralized VR simulation training of mastoidectomy improves subsequent cadaver dissection performance and can potentially improve implementation of VR simulation surgical training.
Decentralized Virtual Reality Mastoidectomy Simulation Training: A Prospective, Mixed-Methods Study
PURPOSE: Virtual reality (VR) training of mastoidectomy is effective in surgical training-particularly if organized as distributed practice. However, centralization of practice facilities is a barrier to implementation of distributed simulation training. Decentralized training could be a potential solution. Here, we aim to assess the feasibility, use, and barriers to decentralized VR mastoidectomy training using a freeware, high-fidelity temporal bone simulator.
METHODS: In a prospective, mixed-methods study, 20 otorhinolaryngology residents were given three months of local access to a VR mastoidectomy simulator. Additionally, trainees were provided a range of learning supports for directed, self-regulated learning. Questionnaire data were collected and focus group interviews conducted. The interviews were analyzed using thematic analysis and compared with quantitative findings.
RESULTS: Participants trained 48.5 h combined and mainly towards the end of the trial. Most participants used between two and four different learning supports. Qualitative analysis revealed five main themes regarding implementation of decentralized simulation training: convenience, time for training, ease of use, evidence for training, and testing.
CONCLUSIONS: Decentralized VR training using a freeware, high-fidelity mastoidectomy simulator is feasible but did not lead to a high training volume or truly distributed practice. Evidence for training was found motivational. Access to training, educational designs, and the role of testing are important for participant motivation and require further evaluation.
Cognitive load and performance in immersive virtual reality versus conventional virtual reality simulation training of laparoscopic surgery: a randomized trial
BACKGROUND: Virtual reality simulators combined with head-mounted displays enable highly immersive virtual reality (VR) for surgical skills training, potentially bridging the gap between the simulation environment and real-life operating room conditions. However, the increased complexity of the learning situation in immersive VR could potentially induce high cognitive load thereby inhibiting performance and learning. This study aims to compare cognitive load and performance in immersive VR and conventional VR simulation training.
METHODS: A randomized controlled trial of residents (n = 31) performing laparoscopic salpingectomies with an ectopic pregnancy in either immersive VR or conventional VR simulation. Cognitive load was estimated by secondary-task reaction time at baseline, and during nonstressor and stressor phases of the procedure. Simulator metrics were used to evaluate performance.
RESULTS: Cognitive load was increased by 66% and 58% during immersive VR and conventional VR simulation, respectively (p < 0.001), compared to baseline. A light stressor induced a further increase in cognitive load by 15.2% and a severe stressor by 43.1% in the immersive VR group compared to 23% (severe stressor) in the conventional VR group. Immersive VR also caused a significantly worse performance on most simulator metrics.
CONCLUSION: Immersive VR simulation training induces a higher cognitive load and results in a poorer performance than conventional VR simulation training in laparoscopy. High extraneous load and element interactivity in the immersive VR are suggested as mechanisms explaining this finding. However, immersive VR offers some potential advantages over conventional VR such as more real-life conditions but we only recommend introducing immersive VR in surgical skills training after initial training in conventional VR.
The effect of distributed virtual reality simulation training on cognitive load during subsequent dissection training
BACKGROUND: Complex tasks such as surgical procedures can induce excessive cognitive load (CL), which can have a negative effect on learning, especially for novices.
AIM: To investigate if repeated and distributed virtual reality (VR) simulation practice induces a lower CL and higher performance in subsequent cadaveric dissection training.
METHODS: In a prospective, controlled cohort study, 37 residents in otorhinolaryngology received VR simulation training either as additional distributed practice prior to course participation (intervention) (9 participants) or as standard practice during the course (control) (28 participants). Cognitive load was estimated as the relative change in secondary-task reaction time during VR simulation and cadaveric procedures.
RESULTS: Structured distributed VR simulation practice resulted in lower mean reaction times (32% vs. 47% for the intervention and control group, respectively, p < 0.01) as well as a superior final-product performance during subsequent cadaveric dissection training.
CONCLUSIONS: Repeated and distributed VR simulation causes a lower CL to be induced when the learning situation is increased in complexity. A suggested mechanism is the formation of mental schemas and reduction of the intrinsic CL. This has potential implications for surgical skills training and suggests that structured, distributed training be systematically implemented in surgical training curricula.
The Effect of a Distributed Virtual Reality Simulation Training Program on Dissection Mastoidectomy Performance
OBJECTIVE: To investigate the effect on final-product performance of a distributed, virtual reality (VR) simulation training program on cadaveric dissection performance and learning curves compared with standard VR simulation training during a temporal bone course.
STUDY DESIGN: Educational interventional cohort study.
SETTING: The national Danish temporal bone courses of 2016 and 2017.
SUBJECTS: Postgraduate year 2 to 5 residents in otorhinolaryngology.
INTERVENTION: Nine participants volunteered for additional VR simulation training (intervention) before the temporal bone course, with training blocks distributed (i.e., separated). The remaining 28 participants received standard VR simulation training during the temporal bone course (control).
MAIN OUTCOME MEASURE: VR simulation and cadaveric dissection final-product performances were analyzed by blinded raters using a 26-item modified Welling Scale.
RESULTS: Distributed VR simulation training before the temporal bone course (intervention) significantly increased dissection final-product performance by 25% compared with standard VR simulation training during the course (control) (mean scores 12.8 points versus 10.3 points, p < 0.01). Distributed and repeated VR simulation practice markedly decreased drilling time. Guidance by the simulator-integrated tutor-function significantly increased final-product performance by 2.3 points compared with nontutored procedures but at the cost of increased drilling time.
CONCLUSION: Skills acquired in a VR simulation environment translate to cadaveric dissection skills and repeated and distributed VR simulation can be used to further increase performance compared with standard VR simulation training during a temporal bone course. Further dissemination of inexpensive VR simulators would allow all future temporal bone course participants to train locally before attending future centralized courses.
Virtual reality simulation training of mastoidectomy - studies on novice performance
Virtual reality (VR) simulation-based training is increasingly used in surgical technical skills training including in temporal bone surgery. The potential of VR simulation in enabling high-quality surgical training is great and VR simulation allows high-stakes and complex procedures such as mastoidectomy to be trained repeatedly, independent of patients and surgical tutors, outside traditional learning environments such as the OR or the temporal bone lab, and with fewer of the constraints of traditional training. This thesis aims to increase the evidence-base of VR simulation training of mastoidectomy and, by studying the final-product performances of novices, investigates the transfer of skills to the current gold-standard training modality of cadaveric dissection, the effect of different practice conditions and simulator-integrated tutoring on performance and retention of skills, and the role of directed, self-regulated learning. Technical skills in mastoidectomy were transferable from the VR simulation environment to cadaveric dissection with significant improvement in performance after directed, self-regulated training in the VR temporal bone simulator. Distributed practice led to a better learning outcome and more consolidated skills than massed practice and also resulted in a more consistent performance after three months of non-practice. Simulator-integrated tutoring accelerated the initial learning curve but also caused over-reliance on tutoring, which resulted in a drop in performance when the simulator-integrated tutor-function was discontinued. The learning curves were highly individual but often plateaued early and at an inadequate level, which related to issues concerning both the procedure and the VR simulator, over-reliance on the tutor function and poor self-assessment skills. Future simulator-integrated automated assessment could potentially resolve some of these issues and provide trainees with both feedback during the procedure and immediate assessment following each procedure. Standard setting by establishing a proficiency level that can be used for mastery learning with deliberate practice could also further sophisticate directed, self-regulated learning in VR simulation-based training. VR simulation-based training should be embedded in a systematic and competency-based training curriculum for high-quality surgical skills training, ultimately leading to improved safety and patient care.
The effect of self-directed virtual reality simulation on dissection training performance in mastoidectomy
OBJECTIVES/HYPOTHESIS: To establish the effect of self-directed virtual reality (VR) simulation training on cadaveric dissection training performance in mastoidectomy and the transferability of skills acquired in VR simulation training to the cadaveric dissection training setting.
STUDY DESIGN: Prospective study.
METHODS: Two cohorts of 20 novice otorhinolaryngology residents received either self-directed VR simulation training before cadaveric dissection training or vice versa. Cadaveric and VR simulation performances were assessed using final-product analysis with three blinded expert raters.
RESULTS: The group receiving VR simulation training before cadaveric dissection had a mean final-product score of 14.9 (95 % confidence interval [CI] [12.9-16.9]) compared with 9.8 (95% CI [8.4-11.1]) in the group not receiving VR simulation training before cadaveric dissection. This 52% increase in performance was statistically significantly (P < 0.0001). A single dissection mastoidectomy did not increase VR simulation performance (P = 0.22).
CONCLUSIONS: Two hours of self-directed VR simulation training was effective in increasing cadaveric dissection mastoidectomy performance and suggests that mastoidectomy skills are transferable from VR simulation to the traditional dissection setting. Virtual reality simulation training can therefore be employed to optimize training, and can spare the use of donated material and instructional resources for more advanced training after basic competencies have been acquired in the VR simulation environment.
LEVEL OF EVIDENCE: NA.
The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial
BACKGROUND: Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training of mastoidectomy.
METHODS: Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem completion exercise (intervention). Participants then completed two post-training virtual procedures for assessment and comparison. Cognitive load during the post-training procedures was estimated by reaction time testing on an integrated secondary task. Final-product analysis by two blinded expert raters was used to assess the virtual mastoidectomy performances.
RESULTS: Participants in the intervention group had a significantly increased cognitive load during the post-training procedures compared with the control group (52 vs. 41 %, p = 0.02). This was also reflected in the final-product performance: the intervention group had a significantly lower final-product score than the control group (13.0 vs. 15.4, p < 0.005).
CONCLUSIONS: Initial instruction using worked examples followed by a problem completion exercise did not reduce the cognitive load or improve the performance of the following procedures in novices. Increased cognitive load when part tasks needed to be integrated in the post-training procedures could be a possible explanation for this. Other instructional designs and methods are needed to lower the cognitive load and improve the performance in virtual reality surgical simulation training of novices.
Notes From the Field: Secondary Task Precision for Cognitive Load Estimation During Virtual Reality Surgical Simulation Training
Cognitive load (CL) theory suggests that working memory can be overloaded in complex learning tasks such as surgical technical skills training, which can impair learning. Valid and feasible methods for estimating the CL in specific learning contexts are necessary before the efficacy of CL-lowering instructional interventions can be established. This study aims to explore secondary task precision for the estimation of CL in virtual reality (VR) surgical simulation and also investigate the effects of CL-modifying factors such as simulator-integrated tutoring and repeated practice. Twenty-four participants were randomized for visual assistance by a simulator-integrated tutor function during the first 5 of 12 repeated mastoidectomy procedures on a VR temporal bone simulator. Secondary task precision was found to be significantly lower during simulation compared with nonsimulation baseline, p < .001. Contrary to expectations, simulator-integrated tutoring and repeated practice did not have an impact on secondary task precision. This finding suggests that even though considerable changes in CL are reflected in secondary task precision, it lacks sensitivity. In contrast, secondary task reaction time could be more sensitive, but requires substantial postprocessing of data. Therefore, future studies on the effect of CL modifying interventions should weigh the pros and cons of the various secondary task measurements.
Cognitive load in distributed and massed practice in virtual reality mastoidectomy simulation
OBJECTIVES/HYPOTHESIS: Cognitive load theory states that working memory is limited. This has implications for learning and suggests that reducing cognitive load (CL) could promote learning and skills acquisition. This study aims to explore the effect of repeated practice and simulator-integrated tutoring on CL in virtual reality (VR) mastoidectomy simulation.
STUDY DESIGN: Prospective trial.
METHODS: Forty novice medical students performed 12 repeated virtual mastoidectomy procedures in the Visible Ear Simulator: 21 completed distributed practice with practice blocks spaced in time and 19 participants completed massed practice (all practices performed in 1 day). Participants were randomized for tutoring with the simulator-integrated tutor function. Cognitive load was estimated by measuring reaction time in a secondary task. Data were analyzed using linear mixed models for repeated measurements.
RESULTS: The mean reaction time increased by 37% during the procedure compared with baseline, demonstrating that the procedure placed substantial cognitive demands. Repeated practice significantly lowered CL in the distributed practice group but not in massed practice group. In addition, CL was found to be further increased by 10.3% in the later and more complex stages of the procedure. The simulator-integrated tutor function did not have an impact on CL.
CONCLUSION: Distributed practice decreased CL in repeated VR mastoidectomy training more consistently than was seen in massed practice. This suggests a possible effect of skills and memory consolidation occurring over time. To optimize technical skills learning, training should be organized as time-distributed practice rather than as a massed block of practice, which is common in skills-training courses.
Novices perform better in virtual reality simulation than in traditional cadaveric dissection training of mastoidectomy
BACKGROUND: Temporal bone surgery requires integration of complex knowledge and technical skills. This can be difficult to accomplish with traditional cadaveric dissection training, which is often organized as single-instance participation in a temporal bone course. Simulator-integrated tutoring in virtual reality (VR) surgical simulators can visually guide the procedure and facilitate self-directed surgical skills acquisition. This study aims to explore the performances of novice otorhinolaryngology residents in a freeware VR simulator and in cadaveric dissection training of mastoidectomy.
METHODS: Thirty-four novice otorhinolaryngology residents performed a single and self-directed mastoidectomy procedure in a freeware VR temporal bone simulator before performing a similar procedure on a cadaveric temporal bone. VR simulation and cadaveric dissection performances were assessed by two blinded expert raters using final product analysis.
RESULTS: Participants achieved a higher mean final product score in VR simulation compared with cadaveric dissection (14.9 and 13.2, respectively; P = 0.02). Significantly more of the participants had their best performance in VR simulation (P = 0.04). No differences in computer experience and interest were found between the group that performed better in VR simulation and the group that performed better in cadaveric dissection.
CONCLUSIONS: Novice performance in a freeware VR temporal bone simulator was significantly better than in cadaveric dissection. The simulator-integrated tutor function and reduced complexity of the procedure in VR simulation could be possible explanations for this finding. VR simulation training could be used in the initial training of novices, reserving dissection training for more advanced training after basic competencies have been acquired with VR simulation.
Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice
IMPORTANCE: Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal in understanding skills acquisition and best-practice implementation and organization of training.
OBJECTIVE: To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training.
DESIGN, SETTING, AND PARTICIPANTS: A prospective trial with a 2 × 2 design was conducted at an academic teaching hospital. Participants included 43 novice medical students. Of these, 21 students completed time-distributed practice from October 14 to November 29, 2013, and a separate group of 19 students completed massed practice on May 16, 17, or 18, 2014. Data analysis was performed from June 6, 2014, to March 3, 2015.
INTERVENTIONS: Participants performed 12 repeated virtual mastoidectomies using a temporal bone surgical simulator in either a distributed (practice blocks spaced in time) or massed (all practice in 1 day) training program with randomization for simulator-integrated tutoring during the first 5 sessions.
MAIN OUTCOMES AND MEASURES: Performance was assessed using a modified Welling Scale for final product analysis by 2 blinded senior otologists.
RESULTS: Compared with the 19 students in the massed practice group, the 21 students in the distributed practice group were older (mean age, 25.1 years), more often male (15 [62%]), and had slightly higher mean gaming frequency (2.3 on a 1-5 Likert scale). Learning curves were established and distributed practice was found to be superior to massed practice, reported as mean end score (95% CI) of 15.7 (14.4-17.0) in distributed practice vs. 13.0 (11.9-14.1) with massed practice (P = .002). Simulator-integrated tutoring accelerated the initial performance, with mean score for tutored sessions of 14.6 (13.9-15.2) vs. 13.4 (12.8-14.0) for corresponding nontutored sessions (P < .01) but at the cost of a drop in performance once tutoring ceased. The performance drop was less with distributed practice, suggesting a protective effect when acquired skills were consolidated over time. The mean performance of the nontutored participants in the distributed practice group plateaued on a score of 16.0 (15.3-16.7) at approximately the ninth repetition, but the individual learning curves were highly variable.
CONCLUSIONS AND RELEVANCE: Novices can acquire basic mastoidectomy competencies with self-directed VR simulation training. Training should be organized with distributed practice, and simulator-integrated tutoring can be useful to accelerate the initial learning curve. Practice should be deliberate and toward a standard set level of proficiency that remains to be defined rather than toward the mean learning curve plateau.