I read with interest the review of cognitive load theory published by Fraser et al.1 Although the authors make excellent points about the application of cognitive load theory to simulation, they use this theory to support the concept that in dual-task simulations, “the secondary task will itself interfere in the learning outcome of interest.”1 Although dual-task simulation may interfere with medical knowledge acquisition among novice learners, health care providers have an urgent need for dual-task training, and this type of simulation should be informed, rather than discouraged, by cognitive load theory.
Interruptions and distractions are common in the emergency department (ED) and the medical wards,2 and studies have shown that clinical tasks that are interrupted are less likely to be completed than uninterrupted tasks.3 In one study, an investigator followed ED physicians for 180-minute periods and found that physicians performed a mean of 67 tasks per study period, with a mean (SD) of 30.9 (9.7) interruptions and 20.7 (6.3) breaks in task.4 Although there is a paucity of data in health care to determine whether interruptions lead to adverse events,5 in a study of pharmacy staff, interruptions and distractions per half hour were significantly associated with errors.6 Although it may be possible to reduce interruptions in some areas of health care such as medication dispensing, in many areas of health care, such as the ED, interruptions are inevitable.2
Despite the high frequency of interruptions among health care providers, training in task switching is lacking in medical schools and is expected to be learned on the job by residents.2 According to cognitive load theory, novice physicians will perform poorly in activities in which they have to task switch because their working memory will become overwhelmed with both the novelty of the patient’s condition and the need to respond to distracting stimuli. Expert physicians, in contrast, should be able to task switch more successfully than novice physicians because experts draw from long-term memory when treating patients, which frees their working memory to process distractions.1 If novice physicians are expected to learn both the management of patient conditions and task switching on the job, it seems very likely that errors will occur during early stages of training because working memory will be overwhelmed by both the need to acquire medical knowledge and the need to task switch.
Data have shown that by practicing complex task switching, learners can reduce the amount that their performance declines when they are asked to task switch.7 Dual-task simulations in which clinicians are ask to switch between different patient scenarios may, therefore, be an excellent tool for developing a schema to manage interruptions, and this, in turn, could lead to reduced medical error rates. In a pilot study of dual-task simulation in second-year internal medicine residents, 3 critical care simulation cases were run simultaneously.8 Eighty-nine percent of participants reported that the simultaneous case format was a more effective way to practice clinical skills that are used in the intensive care unit compared with the standard sequential case format, and one student commented that simultaneous simulations “build skills in multitasking.”8 The residents in this study seemed to recognize the frequency of task switching during critical care rotations and felt that simultaneous simulations were an effective way to practice this skill.8
Training in task switching must, however, take into account cognitive load theory to optimize learner development. I propose that simulation sessions to teach task switching are important but should be distinct from simulations that teach novel medical knowledge. For simulations designed to teach medical knowledge to novice learners, a single case should be used, as working memory should be dedicated to solving the case, and simultaneous simulations would serve only to distract learners and detract from their knowledge acquisition. A distinct simulation experience should be designed for novice learners to teach task switching. In these dual-task simulations, learners can either have 2 to 3 patient scenarios that they manage simultaneously, as in the multiple simultaneous critical care simulations study,8 or can have a single case that they manage while being interrupted periodically by simulation center staff with pages or questions. Importantly, the dual-task simulations designed to teach task switching should only use cases for which the learners are already comfortable with management. If the learners are comfortable with the medical knowledge aspects of the dual-task cases, working memory can then be dedicated to constructing a schema for task switching between multiple patients. The application of cognitive load theory to medical simulation does not preclude dual-task training; rather, it informs the development of a dual-task simulation curriculum that seeks to reduce medical errors by training health care professionals in task switching.
Traci Adams, MD
Department of Pulmonary and
Critical Care Medicine
University of Texas Southwestern
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2015; 10(5): 295–307.
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8. Fraser TN, Genuardi M, McCullough SA, Currier PF, Miloslavsky EM. Observations: a pilot study of multiple simultaneous critical care simulations. J Grad Med Educ
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