- Email: [email protected]
Practical skills teaching in contemporary surgical education: how can educational theory be applied to promote effective learning?
The American Journal of Surgery (2012) 204, 396 – 401
Surgical Education
Practical skills teaching in contemporary surgical education: how can educational theory be applied to promote effective learning? Hazim Sadideen, M.R.C.S.*, Roger Kneebone, Ph.D. Department of Surgery and Cancer, Imperial College London, St. Mary’s Hospital, Praed St., Second Floor QEQM Wing, London W2 1NY, UK KEYWORDS: Surgical education; Practical skills teaching; Effective learning; Surgical skills; Educational theory; Simulation
Abstract BACKGROUND: Teaching practical skills is a core component of undergraduate and postgraduate surgical education. It is crucial to optimize our current learning and teaching models, particularly in a climate of decreased clinical exposure. This review explores the role of educational theory in promoting effective learning in practical skills teaching. METHODS: Peer-reviewed publications, books, and online resources from national bodies (eg, the UK General Medical Council) were reviewed. RESULTS: This review highlights several aspects of surgical education, modeling them on current educational theory. These include the following: (1) acquisition and retention of motor skills (Miller’s triangle; Fitts’ and Posner’s theory), (2) development of expertise after repeated practice and regular reinforcement (Ericsson’s theory), (3) importance of the availability of expert assistance (Vygotsky’s theory), (4) learning within communities of practice (Lave and Wenger’s theory), (5) importance of feedback in learning practical skills (Boud, Schon, and Endes’ theories), and (6) affective component of learning. CONCLUSIONS: It is hoped that new approaches to practical skills teaching are designed in light of our understanding of educational theory. © 2012 Elsevier Inc. All rights reserved.
At the Johns Hopkins Hospital in Baltimore in 1889, Sir William Halsted introduced a German-style residency training system with an emphasis on graded responsibility.1 In the United States, this system remains the cornerstone of surgical training. However, advances in educational theory, in addition to mounting pressures in the clinical environment, have advocated change in this traditional approach to The authors have no conflicts of interest to declare. * Corresponding author. Tel.: ⫹44-203-312-7930; fax: ⫹44-203-3125407. E-mail address: [email protected] Manuscript received October 11, 2011; revised manuscript December 16, 2011
0002-9610/$ - see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2011.12.020
the teaching and acquisition of surgical skills, both technical and nontechnical. A shorter working week for residents in the United Kingdom2 and the United States3 and an emphasis on increasing operating room efficiency contribute to missed educational opportunities in learning surgical skills. In addition, the increased complexity of surgical caseloads and the greater awareness of medicolegal implications (in that it is ethically unacceptable to learn on patients) may minimize trainee exposure to certain surgical fundamentals. The hallmark of current surgical training appears to be sheer volume of exposure, rather than specifically designed curricula.4 Because opportunities for surgical education
H. Sadideen and R. Kneebone
Educational theory and effective learning
through day-to-day work with patients have been reduced, there has been an increase in simulation facilities with formal curricula specifically designed to teach surgical skills. There are now ample data in the literature to support teaching such skills through simulation, with the aim of better preparing trainees for their surgical experience.5 It has become apparent that the teaching of surgical skills can be modeled on established educational theory. This may help explain, for example, how motor skills are acquired and expertise is developed. This review explores the approach of practical skills teaching in contemporary surgical education in light of educational theory. This is potentially a vast topic, and therefore we concentrate on presenting key information from some models of educational theory, critically analyzing the literature, and highlighting how such theory can support the promotion of effective learning. The terms learner and trainee are used interchangeably throughout this article, based on the assumption that the trainee is always the learner here.
Practical Skills Teaching and Learning Teaching practical skills is a core component of undergraduate and postgraduate surgical education. In the United Kingdom, undergraduate medical education standards have been the responsibility of the General Medical Council, as set out in the Medical Act of 1983. Specifically, their report, “Tomorrow’s Doctors,”6 identified certain core skills students were to attain by the time of graduation, and universities and the National Health Service are expected to comply with this requirement. It also paid particular attention to the standards for the delivery of teaching, learning, and assessment. One phrase from that document reads, “In the final year, students must use practical and clinical skills, rehearsing their eventual responsibilities as a Foundation year 1 doctor,” the latter being the equivalent of an intern or postgraduate year 1. The range of skills is diverse, including diagnostic procedures such as measuring blood pressure and taking blood cultures, which are noninvasive and invasive, respectively, and therapeutic procedures such as skin suturing and injecting local anesthetics. In line with this, the Intercollegiate Surgical Curriculum Project,7 which highlights the curriculum for all 9 postgraduate surgical specialties in the United Kingdom, similarly has defined its goals in accordance with the General Medical Council’s core guidance and standards. In this case it is based on “Good Medical Practice,”8 which specifies that surgical education should “cultivate surgeons with the appropriate clinical skills, technical and operative ability,” among other domains that include multiprofessional skills and knowledge. However, it can be difficult to establish when a trainee is competent in performing a practical skill. There must be a measurable outcome that can be assessed. Describing as-
397
sessment methods is far beyond the scope of this review, but should be kept in mind when delivering practical skills teaching to ensure the learner has grasped key concepts. The adage “see one, do one, teach one” is familiar to many trainees. This method fosters a sense of pride and competition in the surgical profession, but also can be applied to general practical skills learning and teaching per se. However, it creates undue tension for the learner, and after an early complication it may inhibit further exploration of a particular skill by the trainee.9 Furthermore, it is no longer appropriate to teach trainees by asking them to perform complex procedures based on “seeing one” and then “doing one.”10 This is where the concept of competence comes in again. In 1990, Miller11 introduced his famous “hierarchical” triangle comprising 4 levels, where from base to pinnacle one “knows,” then “knows how,” then “shows how,” before reaching the final stage of “does.” Thus, in each step toward competence, the trainee progresses through the necessary cognitive and behavioral steps that underlie the next step, building the knowledge that eventually underpins the execution of a specific skill. One drawback, however, is that this triangle appears to assume that competence predicts performance; it is well known, however, that other factors in the workplace also can hinder task execution (such as difficulty intubating a patient if the available equipment is inadequate and there is no available team to help). These represent challenges to everyday learning. Rethans et al12 thus proposed a modification to Miller’s11 triangle, “The Cambridge Model,” taking this into consideration. This model distinguishes competence (what a trainee shows in an assessment situation) from performance (what a trainee shows in real practice), and highlights the need, when appropriate, to assess true clinical performance in addition to true competence at performing a practical skill. Performance builds on competence, but depends on 2 other factors: namely, system-related influences (such as national curricula, General Medical Council regulations, and hospital policies) and individual-related influences (such as mental and physical health, and relationships with peers and family). This model takes this into consideration, highlighting the importance of assessing the global performance and competence of trainees performing a practical skill in an optimal fashion to represent a true clinical encounter.
Motor Skills: Acquisition and Retention It seems logical that successful completion of a practical procedure is based on successful acquisition and execution of psychomotor skills. In the surgical and motor skills literature, the 3-phase theory of motor skill acquisition by Fitts and Posner13 is well known.14 This essentially is composed of 3 phases: the cognitive phase (when the skill is learned), the associative phase (when performance is becoming skilled), and the
398
The American Journal of Surgery, Vol 204, No 3, September 2012
autonomous phase (when the skill has become entirely automatic and can be performed without much thought regarding the task).15 The simplest example to expand on is that of the surgical tie (knot). This is the core practical skill relevant to all surgical specialties, which an experienced surgeon is expected to perform competently and confidently. In the cognitive stage, the learner intellectualizes the task. The learner must understand the mechanics of knot-tying (ie, how to hold the suture, how to place the throws, and how to move his/her hands appropriately). The trainee may perform this in distinct steps with an erratic performance. With continued practice and relevant feedback, the trainee reaches the associative or integrative stage during which knowledge is translated into appropriate motor behavior. The trainee still may be thinking of the next step in hand movements, but should be able to execute the task more fluidly with fewer interruptions. Continued practice gradually results in a smoother performance in the autonomous stage, in which the trainee does not think about how knot-tying is executed, but begins to concentrate on other aspects related to the procedure. Bearing in mind where a trainee lies in this model, the trainer should target practical skills teaching appropriately. For example, particularly when teaching more complex tasks (or when teaching simple tasks to novices such as junior medical students), gross errors occur and often are noticed by the trainer or even the trainee, and are corrected and subsequently are reduced in frequency. After increased opportunities for performing related tasks, the trainee becomes more able to generate improved outcomes more smoothly, swiftly, and with less effort. With trainer encouragement and involvement in the early stages, a competent trainee can reach the autonomous stage. Expert performance represents the highest level of technical skill acquisition. Through extended experience, it is the final result of a gradual improvement in performance. This concept is best elucidated by Ericsson.16,17 According to Ericsson,16,17 most professionals reach a stable, average level of performance and maintain this status quo for the rest of their careers. Surgical experts, consequently, have been defined as experienced surgeons with repeatedly better results than nonexperts. Many professionals probably do not attain true expertise in practical skill acquisition. It seems logical to state that regular practice is hence an important determinant of outcome.18 However, it is apparent that volume alone does not account for the skill level among surgeons because variations in performance have been shown among different surgeons with high volumes of cases. Ericsson16 also argued that the number of hours spent in deliberate practice, rather than just hours spent in surgery, is an important determinant of the level of expertise. Thus, deliberate practice is a critical process requisite for the development of expertise or mastery. Deliberate practice, in the earlier-described example, requires the learner to focus on knot-tying. It involves repeated practice along with coaching and immediate feed-
back on performance by the trainer. The attained level of expertise has been shown to be related closely to time devoted to deliberate practice in the performance of chess players, athletes, and expert musicians.15 In an apprenticeship-based model of surgical education, there are fewer opportunities for deliberate practice. This is where simulation can play a fascinating role. In the United States, in a joint educational offering, the American College of Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons established the Fundamentals of Laparoscopic Surgery. This is a comprehensive education module that includes a hands-on skills training simulation component, a web-based program, and an assessment tool designed to teach surgical residents the fundamental knowledge, technical skills and physiology required in basic laparoscopic surgery. Its aim is to equip those surgeons who have mastered the Fundamentals of Laparoscopic Surgery with knowledge and skills to improve the safety and quality of surgical care delivered to patients. The video materials serve as a robust source of feedback for the learner and additional proctoring is considered optional. By practicing regularly and learning from feedback, trainees can achieve an excellent level of performance.19
An Introduction to Constructivism: A Theory of Knowledge Constructivism argues that human beings generate meaning and knowledge from interactions between their ideas and experiences. Piaget (1896 –1980) referred to these systems of knowledge as schemata. His theory of constructivist learning is now an underlying theme of many education reform movements, having developed a ranging impact on teaching methods in education and on learning theories.20 An in-depth examination of constructivist theory and psychology is fascinating, but cannot be achieved in this review. Simply put, Piaget suggested that through processes of “assimilation” and “accommodation,”21 individuals construct new knowledge based on their experiences. By assimilating, they incorporate the new experience into an already existing framework, with a facilitator instructing appropriately. Thus, the learner always is actively involved. In keeping with practical skills learning, this theory clarifies the fact that trainees are more likely to acquire a practical skill based on a similar previous learning experience. Thus, it would be thought-provoking for trainers to provide analogies when teaching practical skills (eg, comparing the principles of lump excision from the forearm and leg).
The Role of Experts in Providing Assistance Vygotsky (1896 –1934), an early 20th-century Russian psychologist, dramatically influenced the development of
H. Sadideen and R. Kneebone
Educational theory and effective learning
constructivism; his work indeed has now become very popular. He suggested the notion of a “zone of proximal development,” or ZPD, within which the learner could progress in problem solving “in collaboration with more capable peers,” even if unable to do so independently.22,23 Each learner has his/her own ZPD. Some trainees begin at a more advanced ZPD, whereas others do not. This idea subsequently was developed by Bruner24 coining the concept of “scaffolding,” or temporary learning support by an expert tutor. In effect, this already takes place in many teaching environments, but trainees can profit more if this is acknowledged by trainers. This involves allowing the learner to progress within his/her ZPD with the available help of an expert tutor, who can provide feedback to aid in skill acquisition. In addition, Wood25 suggested the idea of “contingent instruction” of available help when required, but that deliberately faded when no longer needed.24,26 Hence, the ZPD could not be more dynamic when it comes to practical skills learning. Each trainee’s ZPD may vary, requiring different levels of peer-support and trainer-prompting, until eventually the skill can be mastered. Thus, a Vygotskian model provides a useful framework for conceptualizing core skill acquisition, such as knot-tying, skin suturing, or more advanced skills such as laparoscopic surgery, allowing the learner to explore personal development while still in his/ her comfort zone (ZPD), before progressing to the level of an expert.
Situated Learning Theory The historical model of technical skills acquisition, in which a trainee learned by shadowing the master, is being replaced by a more modern view of apprenticeship based on “communities of practice and of learning.”27,28 Lave and Wenger26 argued that learning is an inseparable and integral aspect of social practice, rather than a process of internalization of individual experience.26 The core defining component of learning when viewed as a situated activity is the process of “legitimate peripheral participation.”27 In effect, this means that learners participate in communities of practitioners, and to master practical skills trainees are required to move toward full participation in the sociocultural practices of that community.26 This social process could include the learning of practical skills. It is evident that participation is crucial in this theory, and becomes more and more central once the trainee becomes engaged with peers within the same community. This is because Lave and Wenger27 highlight that this apprenticeship is not about providing teaching, but about conferring legitimacy. Here, mastery does not reside in the master, but in the community of practice’s organization, of which the master is a part. Although the work by Lave and Wenger27 is not related directly to health care, it can be seen that to acquire skills successfully, sustained interaction is necessary, which takes
399
time. It would be best to begin teaching simple and low-risk practical skills, during which trainees can achieve identifiable goals within their community of practice. This again identifies the constructivist theme within such a community.
The Affective Component of Learning The emotional component of learning experiences often is neglected because the cognitive issues always seem to dominate. There is, however, a powerful and clear affective element to a learning episode, which may exert a potent effect (positive or negative) on the trainee’s experience.26,29 Most seniors often have shared stories of inspirational mentors in their lives, who positively affected their professional development and vice versa. It is clear that surgical trainees must take ownership of their training, and be responsible for their own development, to achieve adequate skill acquisition. Self-directed learning, reflection, and educational motivation are crucial. Maslow30 described a hierarchical model in which the physical, emotional, and psychological needs of the learner need to be met before effective learning can take place. It thus transpires that to deliver successful practical skills teaching, the trainer needs to create a sustainable ambience that will motivate the trainee, and encourage participation and feedback, positively affecting the learner’s experience. This is a difficult area to examine technically, and ethical approval for a study that specifically puts trainees under psychological pressure may be difficult to justify.
Learning from Practice and Maximizing Feedback A conscientious apprentice and an independent trainee continually should reflect on practice to ensure optimal development as an effective practitioner. Kolb,31 Boud,32 and Schon33 have described processes by which trainees learn from practice, namely experiential learning and reflection. Reflection can be a retrospective activity after the skills teaching session (on action), while performing the skill (in action), and/or forward reflecting (for action); a combination may prove to maximize the reflective process. Feedback from trainers (as argued by Ende34) is as important as trainee feedback35 to aid reflection and development, helping to direct future learning episodes. It can be seen that feedback is a crucial component of learning practical skills, whether defined by the Vygotskian approach (while the trainee is in his/her ZPD), the situated learning theory (in which feedback constitutes continued interaction within the community of practice), or deliberate practice, helping the learner achieve expertise.
400
The American Journal of Surgery, Vol 204, No 3, September 2012
Simulation Simulation has proven to be an excellent adjunct to surgical education. It offers a safe environment in which learners repeatedly can practice a range of clinical skills without endangering patients.5 There is ample evidence to support its use in the acquisition of technical skills.36,37 For example, a recent systematic review and meta-analysis in laparoscopic colorectal surgery provides evidence that trainees can obtain similar clinical results as expert surgeons if supervised by an experienced trainer.38 It has been advocated that the earlier stages of teaching of technical skills should take place outside the operating room; practice is the rule until automaticity in basic skills is achieved.15 This mastery of basic skills allows trainees to focus on more complex issues, both technical and nontechnical, in the operating room. To return to the example of knot tying, the learner who still has to think about how to tie a square knot is less likely to pick up on other teaching that transpires in the operating room compared with the learner who has mastered this core skill. In the working environment, the patient’s clinical needs take precedence over the trainee’s educational needs. Added to the reduced training hours in the current climate, it is prudent to use simulation appropriately, enhancing trainee confidence and, ultimately, patient safety. Kneebone26 evaluated clinical simulations for learning procedural skills in light of educational theory. In summary, “Simulations should allow for sustained, deliberate practice within a safe environment; should provide access to expert tutors, when appropriate; should map onto real-life clinical experience; should provide a supportive, motivational, and learner-centered milieu that is conductive to learning.” It is clear that the earlier-described criteria also can be adapted to practical skills teaching within the context of daily activity, as long as patient safety remains prioritized.
Challenges It must be noted that no system is glitch-free. Often, educational opportunities cannot be used because of the pressure of finishing work on time during a normal working day. This is when maximizing learning opportunities plays an important role. Thus, for example, if a trainer is satisfied that a trainee is confident and competent at knot-tying (having observed and assessed the trainee over time, or even in the coffee room between cases), he/she may allow the trainee to tie knots during the following surgical procedure, adhering to an appropriate educational theory principle. In addition, it is apparent that some trainees acquire skills at different rates,39 representing a difficulty with the learner. This again highlights the importance of simulation and competence assessment to allow those with sufficient technical proficiency to continue training on patients where appropriate.
Last but not least, there are occasional challenges that the trainer may present. These may be owing to personality clashes, obsolete teaching methods, or lack of enthusiasm. In an ideal world, this should be taken into account when appointing educational supervisors for trainees because it can hinder the progression of trainees within their ZPD, affect their learning capabilities within their community of practice, and negatively impact their enthusiasm and motivation to learn. This reinforces the importance of the role the trainer must play in this dynamic teaching environment.
Conclusions Educational theory may predict how practical skills teaching and learning, among many other surgical approaches in contemporary surgical education, can be effective. By creating a framework for evaluating current practical skills teaching, it also creates a framework for novel, untested theories, ultimately promoting consistency in skills teaching. This review touched on some theories, although it must be noted that there are other theories that could have been described and analyzed in greater depth, such as Kolb’s31 experiential theory and its potential role in the learning cycle for skill acquisition. Nevertheless, such theoretical frameworks cannot and should not be tightly boxed. There always tends to be a level of overlap. These are the consequence of slowly shifting yet related historical paradigms. The constructivist theory is an umbrella under which many models share common ground, highlighting the importance of the learner-facilitator interaction, motivation, reflection, and deliberate practice during the learning process. It is important for the trainer to be aware of individual differences among trainees; this can help tailor practical skills teaching appropriately. It is hoped that new approaches to practical skills teaching and learning are designed and implemented on a background of educational theory principles, making medical educators more effective trainers. Many trainers already have adopted an aspect of educational theory in their teaching practices, without being aware. Thus, educating trainers who teach practical skills is of crucial importance. Simulation undoubtedly will play a crucial role here, and inevitably will become a forum for assessing certain skill competencies before progression to real-life scenarios. This hopefully will enhance the development of skills, knowledge, and attitudes among learners, generating an enthusiastic, successful future generation of medical educators.
References 1. Carter BN. The fruition of Halsted’s concept of surgical training. Surgery 1952;32:518 –27. 2. Council Directive 93/104/EC (1993). Available from: http://www. eu-working-directive.co.uk/directives/1993-working-time-directive. htm. Accessed: September 25, 2010.
H. Sadideen and R. Kneebone
Educational theory and effective learning
3. Leach DC. A model for GME: shifting from process to outcomes. A progress report from the Accreditation Council for Graduate Medical Education. Med Educ 2004;38:12– 4. 4. Haluck RS, Krummel TM. Computers and virtual reality for surgical education in the 21st century. Arch Surg 2000;135:786 –92. 5. Kneebone RL, Scott W, Darzi A, et al. Simulation and clinical practice: strengthening the relationship. Med Educ 2004;38:1095–102. 6. General Medical Council. Tomorrow’s doctors. Available from: http:// www.gmc-uk.org/education/undergraduate/tomorrows_doctors_2009. asp. Accessed: September 25, 2011. 7. ISCP. Available from: https://www.iscp.ac.uk/surgical/curr_intro. aspx. Accessed: October 1, 2011. 8. General Medical Council. Good medical practice; 2006. Available from: http://www.gmc-uk.org/guidance/good_medical_practice.asp. Accessed: September 25, 2011. 9. Abela J. Adult learning theories and medical education: a review. Malta Med J 2009;21:11– 8. 10. Grantcharov TP, Reznick RK. Teaching rounds: teaching procedural skills. BMJ 2008;336:1129 –31. 11. Miller GE. The assessment of clinical skills/competence/performance. Acad Med 1990;65:S63–7. 12. Rethans JJ, Norcini JJ, Baron-Maldonaldo M, et al. The relationship between competence and performance: implications for assessing practice performance. Med Educ 2002;36:901–9. 13. Fitts PM, Posner MI. Human Performance. Belmont, CA: Brooks/ Cole; 1967. 14. Kopta JA. The development of motor skills in orthopaedic education. Clin Orthop 1971;75:80 –5. 15. Reznick RK, MacRae H. Teaching surgical skills— changes in the wind. N Engl J Med 2008;256:2664 –9. 16. Ericsson KA. The acquisition of expert performance: an introduction to some of the issues. In: Ericsson KA, ed. The Road to Excellence: The Acquisition of Expert Performance in the Arts and Sciences, Sports and Games. Mahwah, NJ: Lawrence Erlbaum Associates; 1996: 1–50. 17. Ericsson KA. Deliberate practice and the acquisition and maintenance of expert performance in medicine and related domains. Acad Med 2004;79:S70 – 81. 18. Halm EA, Lee C, Chassin MR. Is volume related to outcome in health care? A systematic review and methodologic critique of the literature. Ann Intern Med 2002;137:511–20. 19. Society of American Gastrointestinal and Endoscopic Surgeons. Fundamentals of laparoscopic surgery. Available from: http://www.flsprogram. org/. Accessed: December 8, 2011.
401
20. Whitman N. A review of constructivism: understanding and using a relatively new theory. Fam Med 1993;25:517–52. 21. Block J. Assimilation, accommodation, and the dynamics of personality development. Child Development 1982;53:281–95. 22. Wertsch JV. Vygotsky and the Social Formation of Mind. Cambridge, MA: Harvard University Press; 1985. 23. Vygotsky LS. Thought and Language. Cambridge, MA: MIT Press; 1962. 24. Bruner JS. Toward a Theory of Instruction. Cambridge, MA: Harvard University Press; 1967. 25. Wood D, Wood H, Ainsworth S, et al. On becoming a tutor: toward an cntogenetic model. Cognition and Instruction 1995;13:565– 81. 26. Kneebone R. Evaluating clinical simulations for learning procedural skills: a theory-based approach. Acad Med 2005;80:549 –53. 27. Lave J, Wenger E. Situated Learning. Legitimate Peripheral Participation. Cambridge: Cambridge University Press; 1991. 28. Wenger E. Communities of Practice. Learning, Meaning, and Identity. Cambridge: Cambridge University Press; 1998. 29. Cassar K. Development of an instrument to measure the surgical operating theatre learning environment as perceived by basic surgical trainees. Med Teach 2004;26:260 – 4. 30. Monkhouse S. Learning in the surgical workplace: necessity not luxury. Clin Teach 2010;7:167–70. 31. Kolb DA. Experiential Learning: Experience as the Source of Learning and Development. Englewood-Cliffs, NJ: Prentice-Hall; 1984. 32. Boud, D. A facilitator’s view of adult learning. In D. Boud & V. Griffin (Eds.), Appreciating adults learning: From the learners’ perspective. London: Kogon; 1987. p. 222–39. 33. Schon DA. The Reflective Practitioner. How Professionals Think in Action. New York: Basic Books; 1983. 34. Ende J. Feedback in clinical medical education. JAMA 1983;250: 777– 81. 35. Teunissen PW, Dornan T. The competent novice: lifelong learning at work. BMJ 2008;336:667–9. 36. Aggarwal R, Crochet P, Dias A, et al. Development of a virtual reality training curriculum for laparoscopic cholecystectomy. Br J Surg 2009; 96:1086 –93. 37. Neequaye SK, Aggarwal R, Van Herzeele I, et al. Endovascular skills training and assessment. J Vasc Surg 2007;46:1055– 64. 38. Miskovic D, Wyles SM, Ni M, et al. Systematic review on mentoring and simulation in laparoscopic colorectal surgery. Ann Surg 2010;252: 943–51. 39. Schijven MP, Jakimowicz J. The learning curve on the Xitact LS 500 laparoscopy simulator: profiles of performance. Surg Endosc 2004;18: 121–7.
Surgical Education
Practical skills teaching in contemporary surgical education: how can educational theory be applied to promote effective learning? Hazim Sadideen, M.R.C.S.*, Roger Kneebone, Ph.D. Department of Surgery and Cancer, Imperial College London, St. Mary’s Hospital, Praed St., Second Floor QEQM Wing, London W2 1NY, UK KEYWORDS: Surgical education; Practical skills teaching; Effective learning; Surgical skills; Educational theory; Simulation
Abstract BACKGROUND: Teaching practical skills is a core component of undergraduate and postgraduate surgical education. It is crucial to optimize our current learning and teaching models, particularly in a climate of decreased clinical exposure. This review explores the role of educational theory in promoting effective learning in practical skills teaching. METHODS: Peer-reviewed publications, books, and online resources from national bodies (eg, the UK General Medical Council) were reviewed. RESULTS: This review highlights several aspects of surgical education, modeling them on current educational theory. These include the following: (1) acquisition and retention of motor skills (Miller’s triangle; Fitts’ and Posner’s theory), (2) development of expertise after repeated practice and regular reinforcement (Ericsson’s theory), (3) importance of the availability of expert assistance (Vygotsky’s theory), (4) learning within communities of practice (Lave and Wenger’s theory), (5) importance of feedback in learning practical skills (Boud, Schon, and Endes’ theories), and (6) affective component of learning. CONCLUSIONS: It is hoped that new approaches to practical skills teaching are designed in light of our understanding of educational theory. © 2012 Elsevier Inc. All rights reserved.
At the Johns Hopkins Hospital in Baltimore in 1889, Sir William Halsted introduced a German-style residency training system with an emphasis on graded responsibility.1 In the United States, this system remains the cornerstone of surgical training. However, advances in educational theory, in addition to mounting pressures in the clinical environment, have advocated change in this traditional approach to The authors have no conflicts of interest to declare. * Corresponding author. Tel.: ⫹44-203-312-7930; fax: ⫹44-203-3125407. E-mail address: [email protected] Manuscript received October 11, 2011; revised manuscript December 16, 2011
0002-9610/$ - see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2011.12.020
the teaching and acquisition of surgical skills, both technical and nontechnical. A shorter working week for residents in the United Kingdom2 and the United States3 and an emphasis on increasing operating room efficiency contribute to missed educational opportunities in learning surgical skills. In addition, the increased complexity of surgical caseloads and the greater awareness of medicolegal implications (in that it is ethically unacceptable to learn on patients) may minimize trainee exposure to certain surgical fundamentals. The hallmark of current surgical training appears to be sheer volume of exposure, rather than specifically designed curricula.4 Because opportunities for surgical education
H. Sadideen and R. Kneebone
Educational theory and effective learning
through day-to-day work with patients have been reduced, there has been an increase in simulation facilities with formal curricula specifically designed to teach surgical skills. There are now ample data in the literature to support teaching such skills through simulation, with the aim of better preparing trainees for their surgical experience.5 It has become apparent that the teaching of surgical skills can be modeled on established educational theory. This may help explain, for example, how motor skills are acquired and expertise is developed. This review explores the approach of practical skills teaching in contemporary surgical education in light of educational theory. This is potentially a vast topic, and therefore we concentrate on presenting key information from some models of educational theory, critically analyzing the literature, and highlighting how such theory can support the promotion of effective learning. The terms learner and trainee are used interchangeably throughout this article, based on the assumption that the trainee is always the learner here.
Practical Skills Teaching and Learning Teaching practical skills is a core component of undergraduate and postgraduate surgical education. In the United Kingdom, undergraduate medical education standards have been the responsibility of the General Medical Council, as set out in the Medical Act of 1983. Specifically, their report, “Tomorrow’s Doctors,”6 identified certain core skills students were to attain by the time of graduation, and universities and the National Health Service are expected to comply with this requirement. It also paid particular attention to the standards for the delivery of teaching, learning, and assessment. One phrase from that document reads, “In the final year, students must use practical and clinical skills, rehearsing their eventual responsibilities as a Foundation year 1 doctor,” the latter being the equivalent of an intern or postgraduate year 1. The range of skills is diverse, including diagnostic procedures such as measuring blood pressure and taking blood cultures, which are noninvasive and invasive, respectively, and therapeutic procedures such as skin suturing and injecting local anesthetics. In line with this, the Intercollegiate Surgical Curriculum Project,7 which highlights the curriculum for all 9 postgraduate surgical specialties in the United Kingdom, similarly has defined its goals in accordance with the General Medical Council’s core guidance and standards. In this case it is based on “Good Medical Practice,”8 which specifies that surgical education should “cultivate surgeons with the appropriate clinical skills, technical and operative ability,” among other domains that include multiprofessional skills and knowledge. However, it can be difficult to establish when a trainee is competent in performing a practical skill. There must be a measurable outcome that can be assessed. Describing as-
397
sessment methods is far beyond the scope of this review, but should be kept in mind when delivering practical skills teaching to ensure the learner has grasped key concepts. The adage “see one, do one, teach one” is familiar to many trainees. This method fosters a sense of pride and competition in the surgical profession, but also can be applied to general practical skills learning and teaching per se. However, it creates undue tension for the learner, and after an early complication it may inhibit further exploration of a particular skill by the trainee.9 Furthermore, it is no longer appropriate to teach trainees by asking them to perform complex procedures based on “seeing one” and then “doing one.”10 This is where the concept of competence comes in again. In 1990, Miller11 introduced his famous “hierarchical” triangle comprising 4 levels, where from base to pinnacle one “knows,” then “knows how,” then “shows how,” before reaching the final stage of “does.” Thus, in each step toward competence, the trainee progresses through the necessary cognitive and behavioral steps that underlie the next step, building the knowledge that eventually underpins the execution of a specific skill. One drawback, however, is that this triangle appears to assume that competence predicts performance; it is well known, however, that other factors in the workplace also can hinder task execution (such as difficulty intubating a patient if the available equipment is inadequate and there is no available team to help). These represent challenges to everyday learning. Rethans et al12 thus proposed a modification to Miller’s11 triangle, “The Cambridge Model,” taking this into consideration. This model distinguishes competence (what a trainee shows in an assessment situation) from performance (what a trainee shows in real practice), and highlights the need, when appropriate, to assess true clinical performance in addition to true competence at performing a practical skill. Performance builds on competence, but depends on 2 other factors: namely, system-related influences (such as national curricula, General Medical Council regulations, and hospital policies) and individual-related influences (such as mental and physical health, and relationships with peers and family). This model takes this into consideration, highlighting the importance of assessing the global performance and competence of trainees performing a practical skill in an optimal fashion to represent a true clinical encounter.
Motor Skills: Acquisition and Retention It seems logical that successful completion of a practical procedure is based on successful acquisition and execution of psychomotor skills. In the surgical and motor skills literature, the 3-phase theory of motor skill acquisition by Fitts and Posner13 is well known.14 This essentially is composed of 3 phases: the cognitive phase (when the skill is learned), the associative phase (when performance is becoming skilled), and the
398
The American Journal of Surgery, Vol 204, No 3, September 2012
autonomous phase (when the skill has become entirely automatic and can be performed without much thought regarding the task).15 The simplest example to expand on is that of the surgical tie (knot). This is the core practical skill relevant to all surgical specialties, which an experienced surgeon is expected to perform competently and confidently. In the cognitive stage, the learner intellectualizes the task. The learner must understand the mechanics of knot-tying (ie, how to hold the suture, how to place the throws, and how to move his/her hands appropriately). The trainee may perform this in distinct steps with an erratic performance. With continued practice and relevant feedback, the trainee reaches the associative or integrative stage during which knowledge is translated into appropriate motor behavior. The trainee still may be thinking of the next step in hand movements, but should be able to execute the task more fluidly with fewer interruptions. Continued practice gradually results in a smoother performance in the autonomous stage, in which the trainee does not think about how knot-tying is executed, but begins to concentrate on other aspects related to the procedure. Bearing in mind where a trainee lies in this model, the trainer should target practical skills teaching appropriately. For example, particularly when teaching more complex tasks (or when teaching simple tasks to novices such as junior medical students), gross errors occur and often are noticed by the trainer or even the trainee, and are corrected and subsequently are reduced in frequency. After increased opportunities for performing related tasks, the trainee becomes more able to generate improved outcomes more smoothly, swiftly, and with less effort. With trainer encouragement and involvement in the early stages, a competent trainee can reach the autonomous stage. Expert performance represents the highest level of technical skill acquisition. Through extended experience, it is the final result of a gradual improvement in performance. This concept is best elucidated by Ericsson.16,17 According to Ericsson,16,17 most professionals reach a stable, average level of performance and maintain this status quo for the rest of their careers. Surgical experts, consequently, have been defined as experienced surgeons with repeatedly better results than nonexperts. Many professionals probably do not attain true expertise in practical skill acquisition. It seems logical to state that regular practice is hence an important determinant of outcome.18 However, it is apparent that volume alone does not account for the skill level among surgeons because variations in performance have been shown among different surgeons with high volumes of cases. Ericsson16 also argued that the number of hours spent in deliberate practice, rather than just hours spent in surgery, is an important determinant of the level of expertise. Thus, deliberate practice is a critical process requisite for the development of expertise or mastery. Deliberate practice, in the earlier-described example, requires the learner to focus on knot-tying. It involves repeated practice along with coaching and immediate feed-
back on performance by the trainer. The attained level of expertise has been shown to be related closely to time devoted to deliberate practice in the performance of chess players, athletes, and expert musicians.15 In an apprenticeship-based model of surgical education, there are fewer opportunities for deliberate practice. This is where simulation can play a fascinating role. In the United States, in a joint educational offering, the American College of Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons established the Fundamentals of Laparoscopic Surgery. This is a comprehensive education module that includes a hands-on skills training simulation component, a web-based program, and an assessment tool designed to teach surgical residents the fundamental knowledge, technical skills and physiology required in basic laparoscopic surgery. Its aim is to equip those surgeons who have mastered the Fundamentals of Laparoscopic Surgery with knowledge and skills to improve the safety and quality of surgical care delivered to patients. The video materials serve as a robust source of feedback for the learner and additional proctoring is considered optional. By practicing regularly and learning from feedback, trainees can achieve an excellent level of performance.19
An Introduction to Constructivism: A Theory of Knowledge Constructivism argues that human beings generate meaning and knowledge from interactions between their ideas and experiences. Piaget (1896 –1980) referred to these systems of knowledge as schemata. His theory of constructivist learning is now an underlying theme of many education reform movements, having developed a ranging impact on teaching methods in education and on learning theories.20 An in-depth examination of constructivist theory and psychology is fascinating, but cannot be achieved in this review. Simply put, Piaget suggested that through processes of “assimilation” and “accommodation,”21 individuals construct new knowledge based on their experiences. By assimilating, they incorporate the new experience into an already existing framework, with a facilitator instructing appropriately. Thus, the learner always is actively involved. In keeping with practical skills learning, this theory clarifies the fact that trainees are more likely to acquire a practical skill based on a similar previous learning experience. Thus, it would be thought-provoking for trainers to provide analogies when teaching practical skills (eg, comparing the principles of lump excision from the forearm and leg).
The Role of Experts in Providing Assistance Vygotsky (1896 –1934), an early 20th-century Russian psychologist, dramatically influenced the development of
H. Sadideen and R. Kneebone
Educational theory and effective learning
constructivism; his work indeed has now become very popular. He suggested the notion of a “zone of proximal development,” or ZPD, within which the learner could progress in problem solving “in collaboration with more capable peers,” even if unable to do so independently.22,23 Each learner has his/her own ZPD. Some trainees begin at a more advanced ZPD, whereas others do not. This idea subsequently was developed by Bruner24 coining the concept of “scaffolding,” or temporary learning support by an expert tutor. In effect, this already takes place in many teaching environments, but trainees can profit more if this is acknowledged by trainers. This involves allowing the learner to progress within his/her ZPD with the available help of an expert tutor, who can provide feedback to aid in skill acquisition. In addition, Wood25 suggested the idea of “contingent instruction” of available help when required, but that deliberately faded when no longer needed.24,26 Hence, the ZPD could not be more dynamic when it comes to practical skills learning. Each trainee’s ZPD may vary, requiring different levels of peer-support and trainer-prompting, until eventually the skill can be mastered. Thus, a Vygotskian model provides a useful framework for conceptualizing core skill acquisition, such as knot-tying, skin suturing, or more advanced skills such as laparoscopic surgery, allowing the learner to explore personal development while still in his/ her comfort zone (ZPD), before progressing to the level of an expert.
Situated Learning Theory The historical model of technical skills acquisition, in which a trainee learned by shadowing the master, is being replaced by a more modern view of apprenticeship based on “communities of practice and of learning.”27,28 Lave and Wenger26 argued that learning is an inseparable and integral aspect of social practice, rather than a process of internalization of individual experience.26 The core defining component of learning when viewed as a situated activity is the process of “legitimate peripheral participation.”27 In effect, this means that learners participate in communities of practitioners, and to master practical skills trainees are required to move toward full participation in the sociocultural practices of that community.26 This social process could include the learning of practical skills. It is evident that participation is crucial in this theory, and becomes more and more central once the trainee becomes engaged with peers within the same community. This is because Lave and Wenger27 highlight that this apprenticeship is not about providing teaching, but about conferring legitimacy. Here, mastery does not reside in the master, but in the community of practice’s organization, of which the master is a part. Although the work by Lave and Wenger27 is not related directly to health care, it can be seen that to acquire skills successfully, sustained interaction is necessary, which takes
399
time. It would be best to begin teaching simple and low-risk practical skills, during which trainees can achieve identifiable goals within their community of practice. This again identifies the constructivist theme within such a community.
The Affective Component of Learning The emotional component of learning experiences often is neglected because the cognitive issues always seem to dominate. There is, however, a powerful and clear affective element to a learning episode, which may exert a potent effect (positive or negative) on the trainee’s experience.26,29 Most seniors often have shared stories of inspirational mentors in their lives, who positively affected their professional development and vice versa. It is clear that surgical trainees must take ownership of their training, and be responsible for their own development, to achieve adequate skill acquisition. Self-directed learning, reflection, and educational motivation are crucial. Maslow30 described a hierarchical model in which the physical, emotional, and psychological needs of the learner need to be met before effective learning can take place. It thus transpires that to deliver successful practical skills teaching, the trainer needs to create a sustainable ambience that will motivate the trainee, and encourage participation and feedback, positively affecting the learner’s experience. This is a difficult area to examine technically, and ethical approval for a study that specifically puts trainees under psychological pressure may be difficult to justify.
Learning from Practice and Maximizing Feedback A conscientious apprentice and an independent trainee continually should reflect on practice to ensure optimal development as an effective practitioner. Kolb,31 Boud,32 and Schon33 have described processes by which trainees learn from practice, namely experiential learning and reflection. Reflection can be a retrospective activity after the skills teaching session (on action), while performing the skill (in action), and/or forward reflecting (for action); a combination may prove to maximize the reflective process. Feedback from trainers (as argued by Ende34) is as important as trainee feedback35 to aid reflection and development, helping to direct future learning episodes. It can be seen that feedback is a crucial component of learning practical skills, whether defined by the Vygotskian approach (while the trainee is in his/her ZPD), the situated learning theory (in which feedback constitutes continued interaction within the community of practice), or deliberate practice, helping the learner achieve expertise.
400
The American Journal of Surgery, Vol 204, No 3, September 2012
Simulation Simulation has proven to be an excellent adjunct to surgical education. It offers a safe environment in which learners repeatedly can practice a range of clinical skills without endangering patients.5 There is ample evidence to support its use in the acquisition of technical skills.36,37 For example, a recent systematic review and meta-analysis in laparoscopic colorectal surgery provides evidence that trainees can obtain similar clinical results as expert surgeons if supervised by an experienced trainer.38 It has been advocated that the earlier stages of teaching of technical skills should take place outside the operating room; practice is the rule until automaticity in basic skills is achieved.15 This mastery of basic skills allows trainees to focus on more complex issues, both technical and nontechnical, in the operating room. To return to the example of knot tying, the learner who still has to think about how to tie a square knot is less likely to pick up on other teaching that transpires in the operating room compared with the learner who has mastered this core skill. In the working environment, the patient’s clinical needs take precedence over the trainee’s educational needs. Added to the reduced training hours in the current climate, it is prudent to use simulation appropriately, enhancing trainee confidence and, ultimately, patient safety. Kneebone26 evaluated clinical simulations for learning procedural skills in light of educational theory. In summary, “Simulations should allow for sustained, deliberate practice within a safe environment; should provide access to expert tutors, when appropriate; should map onto real-life clinical experience; should provide a supportive, motivational, and learner-centered milieu that is conductive to learning.” It is clear that the earlier-described criteria also can be adapted to practical skills teaching within the context of daily activity, as long as patient safety remains prioritized.
Challenges It must be noted that no system is glitch-free. Often, educational opportunities cannot be used because of the pressure of finishing work on time during a normal working day. This is when maximizing learning opportunities plays an important role. Thus, for example, if a trainer is satisfied that a trainee is confident and competent at knot-tying (having observed and assessed the trainee over time, or even in the coffee room between cases), he/she may allow the trainee to tie knots during the following surgical procedure, adhering to an appropriate educational theory principle. In addition, it is apparent that some trainees acquire skills at different rates,39 representing a difficulty with the learner. This again highlights the importance of simulation and competence assessment to allow those with sufficient technical proficiency to continue training on patients where appropriate.
Last but not least, there are occasional challenges that the trainer may present. These may be owing to personality clashes, obsolete teaching methods, or lack of enthusiasm. In an ideal world, this should be taken into account when appointing educational supervisors for trainees because it can hinder the progression of trainees within their ZPD, affect their learning capabilities within their community of practice, and negatively impact their enthusiasm and motivation to learn. This reinforces the importance of the role the trainer must play in this dynamic teaching environment.
Conclusions Educational theory may predict how practical skills teaching and learning, among many other surgical approaches in contemporary surgical education, can be effective. By creating a framework for evaluating current practical skills teaching, it also creates a framework for novel, untested theories, ultimately promoting consistency in skills teaching. This review touched on some theories, although it must be noted that there are other theories that could have been described and analyzed in greater depth, such as Kolb’s31 experiential theory and its potential role in the learning cycle for skill acquisition. Nevertheless, such theoretical frameworks cannot and should not be tightly boxed. There always tends to be a level of overlap. These are the consequence of slowly shifting yet related historical paradigms. The constructivist theory is an umbrella under which many models share common ground, highlighting the importance of the learner-facilitator interaction, motivation, reflection, and deliberate practice during the learning process. It is important for the trainer to be aware of individual differences among trainees; this can help tailor practical skills teaching appropriately. It is hoped that new approaches to practical skills teaching and learning are designed and implemented on a background of educational theory principles, making medical educators more effective trainers. Many trainers already have adopted an aspect of educational theory in their teaching practices, without being aware. Thus, educating trainers who teach practical skills is of crucial importance. Simulation undoubtedly will play a crucial role here, and inevitably will become a forum for assessing certain skill competencies before progression to real-life scenarios. This hopefully will enhance the development of skills, knowledge, and attitudes among learners, generating an enthusiastic, successful future generation of medical educators.
References 1. Carter BN. The fruition of Halsted’s concept of surgical training. Surgery 1952;32:518 –27. 2. Council Directive 93/104/EC (1993). Available from: http://www. eu-working-directive.co.uk/directives/1993-working-time-directive. htm. Accessed: September 25, 2010.
H. Sadideen and R. Kneebone
Educational theory and effective learning
3. Leach DC. A model for GME: shifting from process to outcomes. A progress report from the Accreditation Council for Graduate Medical Education. Med Educ 2004;38:12– 4. 4. Haluck RS, Krummel TM. Computers and virtual reality for surgical education in the 21st century. Arch Surg 2000;135:786 –92. 5. Kneebone RL, Scott W, Darzi A, et al. Simulation and clinical practice: strengthening the relationship. Med Educ 2004;38:1095–102. 6. General Medical Council. Tomorrow’s doctors. Available from: http:// www.gmc-uk.org/education/undergraduate/tomorrows_doctors_2009. asp. Accessed: September 25, 2011. 7. ISCP. Available from: https://www.iscp.ac.uk/surgical/curr_intro. aspx. Accessed: October 1, 2011. 8. General Medical Council. Good medical practice; 2006. Available from: http://www.gmc-uk.org/guidance/good_medical_practice.asp. Accessed: September 25, 2011. 9. Abela J. Adult learning theories and medical education: a review. Malta Med J 2009;21:11– 8. 10. Grantcharov TP, Reznick RK. Teaching rounds: teaching procedural skills. BMJ 2008;336:1129 –31. 11. Miller GE. The assessment of clinical skills/competence/performance. Acad Med 1990;65:S63–7. 12. Rethans JJ, Norcini JJ, Baron-Maldonaldo M, et al. The relationship between competence and performance: implications for assessing practice performance. Med Educ 2002;36:901–9. 13. Fitts PM, Posner MI. Human Performance. Belmont, CA: Brooks/ Cole; 1967. 14. Kopta JA. The development of motor skills in orthopaedic education. Clin Orthop 1971;75:80 –5. 15. Reznick RK, MacRae H. Teaching surgical skills— changes in the wind. N Engl J Med 2008;256:2664 –9. 16. Ericsson KA. The acquisition of expert performance: an introduction to some of the issues. In: Ericsson KA, ed. The Road to Excellence: The Acquisition of Expert Performance in the Arts and Sciences, Sports and Games. Mahwah, NJ: Lawrence Erlbaum Associates; 1996: 1–50. 17. Ericsson KA. Deliberate practice and the acquisition and maintenance of expert performance in medicine and related domains. Acad Med 2004;79:S70 – 81. 18. Halm EA, Lee C, Chassin MR. Is volume related to outcome in health care? A systematic review and methodologic critique of the literature. Ann Intern Med 2002;137:511–20. 19. Society of American Gastrointestinal and Endoscopic Surgeons. Fundamentals of laparoscopic surgery. Available from: http://www.flsprogram. org/. Accessed: December 8, 2011.
401
20. Whitman N. A review of constructivism: understanding and using a relatively new theory. Fam Med 1993;25:517–52. 21. Block J. Assimilation, accommodation, and the dynamics of personality development. Child Development 1982;53:281–95. 22. Wertsch JV. Vygotsky and the Social Formation of Mind. Cambridge, MA: Harvard University Press; 1985. 23. Vygotsky LS. Thought and Language. Cambridge, MA: MIT Press; 1962. 24. Bruner JS. Toward a Theory of Instruction. Cambridge, MA: Harvard University Press; 1967. 25. Wood D, Wood H, Ainsworth S, et al. On becoming a tutor: toward an cntogenetic model. Cognition and Instruction 1995;13:565– 81. 26. Kneebone R. Evaluating clinical simulations for learning procedural skills: a theory-based approach. Acad Med 2005;80:549 –53. 27. Lave J, Wenger E. Situated Learning. Legitimate Peripheral Participation. Cambridge: Cambridge University Press; 1991. 28. Wenger E. Communities of Practice. Learning, Meaning, and Identity. Cambridge: Cambridge University Press; 1998. 29. Cassar K. Development of an instrument to measure the surgical operating theatre learning environment as perceived by basic surgical trainees. Med Teach 2004;26:260 – 4. 30. Monkhouse S. Learning in the surgical workplace: necessity not luxury. Clin Teach 2010;7:167–70. 31. Kolb DA. Experiential Learning: Experience as the Source of Learning and Development. Englewood-Cliffs, NJ: Prentice-Hall; 1984. 32. Boud, D. A facilitator’s view of adult learning. In D. Boud & V. Griffin (Eds.), Appreciating adults learning: From the learners’ perspective. London: Kogon; 1987. p. 222–39. 33. Schon DA. The Reflective Practitioner. How Professionals Think in Action. New York: Basic Books; 1983. 34. Ende J. Feedback in clinical medical education. JAMA 1983;250: 777– 81. 35. Teunissen PW, Dornan T. The competent novice: lifelong learning at work. BMJ 2008;336:667–9. 36. Aggarwal R, Crochet P, Dias A, et al. Development of a virtual reality training curriculum for laparoscopic cholecystectomy. Br J Surg 2009; 96:1086 –93. 37. Neequaye SK, Aggarwal R, Van Herzeele I, et al. Endovascular skills training and assessment. J Vasc Surg 2007;46:1055– 64. 38. Miskovic D, Wyles SM, Ni M, et al. Systematic review on mentoring and simulation in laparoscopic colorectal surgery. Ann Surg 2010;252: 943–51. 39. Schijven MP, Jakimowicz J. The learning curve on the Xitact LS 500 laparoscopy simulator: profiles of performance. Surg Endosc 2004;18: 121–7.